View source for Prosthesis

{{short description|Artificial device that replaces a missing body part}}
[[File:Disabled Soldier's War Job- Producing Artificial Limbs, UK, c 1944 D17829.jpg|thumb|A factory worker with a prosthetic arm using a [[lathe]] to produce artificial limbs {{circa|1944}}]]{{Hatnote|For the sound change in linguistics, see [[Prothesis (linguistics)|Prothesis]].}}
In [[medicine]], a '''prosthesis''' ({{plural form}}: '''prostheses'''; from {{langx|grc|πρόσθεσις|prósthesis|addition, application, attachment}}),<ref>{{LSJ|pro/sqesis|πρόσθεσις|cite}}</ref> or a '''prosthetic implant''',<ref>{{cite web |url=https://www.theengineer.co.uk/prosthetic-implant-wrist-movement/|title=Prosthetic implant provides realistic wrist movement to amputees|first=Stuart|last=Nathan|date=28 November 2018|access-date=2019-01-30 }}</ref><ref>{{LSJ|pro/sqesis|πρόσθεσις|cite}}</ref> is an artificial device that replaces a missing body part, which may be lost through [[physical trauma]], disease, or a condition present at birth ([[Congenital|congenital disorder]]). Prostheses may restore the normal functions of the missing body part,<ref name="madehow.com">{{cite web|url=http://www.madehow.com/Volume-1/Artificial-Limb.html|title=How artificial limb is made – material, manufacture, making, used, parts, components, structure, procedure|website=www.madehow.com|language=en|access-date=2017-10-24}}</ref> or may perform a cosmetic function.

A person who has undergone an amputation is sometimes referred to as an [[Amputation|amputee]], however, this term may be offensive.<ref>{{Cite web |title=Disability Language Style Guide {{!}} National Center on Disability and Journalism |url=https://ncdj.org/style-guide/#:~:text=Amputation/amputee&text=People%20who%20have%20undergone%20an,an%20amputation%E2%80%9D%20is%20generally%20acceptable. |access-date=2024-10-26 |language=en-US}}</ref> Rehabilitation for someone with an amputation is primarily coordinated by a [[Physical medicine and rehabilitation|physiatrist]] as part of an inter-disciplinary team consisting of physiatrists, prosthetists, nurses, physical therapists, and occupational therapists.<ref>{{Cite web|url=http://www.cumc.columbia.edu/rehab/staywell/document.php|title=Physical Medicine and Rehabilitation Treatment Team|website=Department of Rehabilitation and Regenerative Medicine|language=en|access-date=2019-02-24}}</ref> Prostheses can be created by hand or with [[computer-aided design]] (CAD), a software interface that helps creators design and analyze the creation with computer-generated [[Technical drawing|2-D]] and [[3D computer graphics|3-D graphics]] as well as analysis and optimization tools.<ref>{{Cite web|url=http://www.oandplibrary.org/alp/chap04-01.asp|title=4: Prosthetic Management: Overview, Methods, and Materials {{!}} O&P Virtual Library|website=www.oandplibrary.org|access-date=2017-10-24}}</ref>

==Types==
A person's prosthetic device should be designed and assembled to meet their individual appearance and functional needs. Depending on personal circumstances, co-morbidities, budget or health insurance coverage, and access to medical care, decisions may need to balance aesthetics and function. In addition, for some individuals, a myoelectric device, a body-powered device, or an activity-specific device may be appropriate options. The person's future goals and vocational aspirations and potential capabilities may help them choose between one or more devices.{{Citation needed|date=April 2025}}

[[Craniofacial prosthesis|Craniofacial prostheses]]
include intra-oral and extra-oral prostheses. Extra-oral prostheses are further divided into hemifacial, auricular (ear), nasal, [[Orbital prosthesis|orbital]] and [[Ocular prosthesis|ocular]]. Intra-oral prostheses include [[dental prostheses]], such as [[dentures]], [[palatal obturator|obturators]], and [[dental implant]]s.

Prostheses of the neck include [[larynx]] [[Electrolarynx|substitutes]], [[Vertebrate trachea|trachea]] and upper [[esophagus|esophageal]] replacements,

Some prostheses of the torso include [[breast prostheses]] which may be either single or bilateral, full breast devices or [[Nipple prosthesis|nipple prostheses]].

[[Penile implant|Penile prostheses]] are used to treat [[erectile dysfunction]], perform [[phalloplasty]] procedures in men, and to build a new penis in [[Sex reassignment surgery (female-to-male)|female-to-male gender reassignment surgeries]].

===Limb prostheses===
[[Limb (anatomy)|Limb]] prostheses include both upper- and lower-extremity prostheses.

'''Upper-extremity prostheses''' are used at varying levels of amputation: forequarter, shoulder disarticulation, transhumeral prosthesis, elbow disarticulation, transradial prosthesis, wrist disarticulation, full hand, partial hand, finger, partial finger. A transradial prosthesis is an artificial limb that replaces an arm missing below the elbow.
[[File:Army prosthetic.jpg|thumb|241x241px|An example of two upper-extremity prosthetics, one body-powered (right arm), and another [[Implantable myoelectric sensors|myoelectric]] (left arm)]]
Upper limb prostheses can be categorized in three main categories: Passive devices, Body Powered devices, and Externally Powered (myoelectric) devices. Passive devices can either be passive hands, mainly used for cosmetic purposes, or passive tools, mainly used for specific activities (e.g. leisure or vocational). An extensive overview and classification of passive devices can be found in a literature review by Maat ''et.al.''<ref name="Review Passive Prosthetic Hands">{{cite journal|last1=Maat|first1=Bartjan|last2=Smit|first2=Gerwin|last3=Plettenburg|first3=Dick|last4=Breedveld|first4=Paul|title=Passive prosthetic hands and tools: A literature review|journal=Prosthetics and Orthotics International|date=1 March 2017|doi=10.1177/0309364617691622|pmid=28190380|pmc=5810914|language=en|volume=42|issue=1|pages=66–74}}</ref> A passive device can be static, meaning the device has no movable parts, or it can be adjustable, meaning its configuration can be adjusted (e.g. adjustable hand opening). Despite the absence of active grasping, passive devices are very useful in bimanual tasks that require fixation or support of an object, or for gesticulation in social interaction. According to scientific data a third of the upper limb amputees worldwide use a passive prosthetic hand.<ref name="Review Passive Prosthetic Hands" /> Body Powered or cable-operated limbs work by attaching a harness and cable around the opposite shoulder of the damaged arm. A recent body-powered approach has explored the utilization of the user's breathing to power and control the prosthetic hand to help eliminate actuation cable and harness.<ref>{{cite journal |last1=Nagaraja |first1=Vikranth H. |last2=da Ponte Lopes |first2=Jhonatan |last3=Bergmann |first3=Jeroen H. M. |title=Reimagining Prosthetic Control: A Novel Body-Powered Prosthetic System for Simultaneous Control and Actuation |journal=Prosthesis |date=September 2022 |volume=4 |issue=3 |pages=394–413 |doi=10.3390/prosthesis4030032|doi-access=free }}</ref><ref>{{cite journal |last1=Nagaraja |first1=Vikranth H. |last2=Moulic |first2=Soikat Ghosh |last3=D'souza |first3=Jennifer V. |last4=Limesh |first4=M. |last5=Walters |first5=Peter |last6=Bergmann |first6=Jeroen H. M. |title=A Novel Respiratory Control and Actuation System for Upper-Limb Prosthesis Users: Clinical Evaluation Study |journal=IEEE Access |date=December 2022 |volume=10 |pages=128764–128778 |doi=10.1109/ACCESS.2022.3226697|bibcode=2022IEEEA..10l8764N |s2cid=254339929 }}</ref><ref>{{cite news |title=Oxford researchers develop breathing-powered prosthetic hand |url=https://www.bbc.co.uk/news/uk-england-oxfordshire-63972189 |work=BBC News |date=14 December 2022}}</ref> The third category of available prosthetic devices comprises myoelectric arms. This particular class of devices distinguishes itself from the previous ones due to the inclusion of a battery system. This battery serves the dual purpose of providing energy for both actuation and sensing components. While actuation predominantly relies on motor or pneumatic systems,<ref>{{Cite journal |last1=Belter |first1=Joseph T. |last2=Segil |first2=Jacob L. |last3=Dollar |first3=Aaron M. |last4=Weir |first4=Richard F. |date=2013 |title=Mechanical design and performance specifications of anthropomorphic prosthetic hands: A review |journal=The Journal of Rehabilitation Research and Development |volume=50 |issue=5 |pages=599–618 |doi=10.1682/jrrd.2011.10.0188 |pmid=24013909 |issn=0748-7711}}</ref> a variety of solutions have been explored for capturing muscle activity, including techniques such as [[Electromyography]], Sonomyography, Myokinetic, and others.<ref>{{Cite journal |last1=Scheme |first1=Erik |last2=Englehart |first2=Kevin |date=2011 |title=Electromyogram pattern recognition for control of powered upper-limb prostheses: State of the art and challenges for clinical use |journal=The Journal of Rehabilitation Research and Development |volume=48 |issue=6 |pages=643–659 |doi=10.1682/jrrd.2010.09.0177 |pmid=21938652 |s2cid=14883575 |issn=0748-7711}}</ref><ref>{{Cite journal |last1=Nazari |first1=Vaheh |last2=Zheng |first2=Yong-Ping |date=2023-02-08 |title=Controlling Upper Limb Prostheses Using Sonomyography (SMG): A Review |journal=Sensors |language=en |volume=23 |issue=4 |page=1885 |doi=10.3390/s23041885 |issn=1424-8220 |pmc=9959820 |pmid=36850483 |bibcode=2023Senso..23.1885N |doi-access=free }}</ref><ref>{{Cite journal |last1=Clemente |first1=Francesco |last2=Ianniciello |first2=Valerio |last3=Gherardini |first3=Marta |last4=Cipriani |first4=Christian |date=2019-07-17 |title=Development of an Embedded Myokinetic Prosthetic Hand Controller |journal=Sensors |language=en |volume=19 |issue=14 |page=3137 |doi=10.3390/s19143137 |issn=1424-8220 |pmc=6679265 |pmid=31319463 |bibcode=2019Senso..19.3137C |doi-access=free }}</ref> These methods function by detecting the minute electrical currents generated by contracted muscles during [[Arm|upper arm]] movement, typically employing electrodes or other suitable tools. Subsequently, these acquired signals are converted into gripping patterns or postures that the artificial hand will then execute.

In the prosthetics industry, a trans-radial prosthetic arm is often referred to as a "BE" or below elbow prosthesis.

'''Lower-extremity prostheses''' provide replacements at varying levels of amputation. These include [[Hip replacement|hip disarticulation]], transfemoral prosthesis, knee disarticulation, transtibial prosthesis, Syme's amputation, foot, partial foot, and toe. The two main subcategories of lower extremity prosthetic devices are trans-tibial (any amputation transecting the tibia bone or a congenital anomaly resulting in a tibial deficiency) and trans-femoral (any amputation transecting the femur bone or a congenital anomaly resulting in a femoral deficiency).{{Citation needed|reason=in many sciences they are referred to as foreceps|date=August 2019}}

A transfemoral prosthesis is an artificial limb that replaces a leg missing above the knee. Transfemoral amputees can have a very difficult time regaining normal movement. In general, a transfemoral amputee must use approximately 80% more energy to walk than a person with two whole legs.<ref name="four" /> This is due to the complexities in movement associated with the knee. In newer and more improved designs, hydraulics, carbon fiber, mechanical linkages, motors, computer microprocessors, and innovative combinations of these technologies are employed to give more control to the user. In the prosthetics industry, a trans-femoral prosthetic leg is often referred to as an "AK" or above the knee prosthesis.

A transtibial prosthesis is an artificial limb that replaces a leg missing below the knee. A transtibial amputee is usually able to regain normal movement more readily than someone with a transfemoral amputation, due in large part to retaining the knee, which allows for easier movement. Lower extremity prosthetics describe artificially replaced limbs located at the hip level or lower. In the prosthetics industry, a trans-tibial prosthetic leg is often referred to as a "BK" or below the knee prosthesis.

Prostheses are manufactured and fit by clinical prosthetists. Prosthetists are healthcare professionals responsible for making, fitting, and adjusting prostheses and for lower limb prostheses will assess both gait and prosthetic alignment. Once a prosthesis has been fit and adjusted by a prosthetist, a rehabilitation physiotherapist (called physical therapist in America) will help teach a new prosthetic user to walk with a leg prosthesis. To do so, the physical therapist may provide verbal instructions and may also help guide the person using touch or tactile cues. This may be done in a clinic or home. There is some research suggesting that such training in the home may be more successful if the treatment includes the use of a treadmill.<ref>{{Cite journal|last1=Highsmith|first1=M. Jason|last2=Andrews|first2=Casey R.|last3=Millman|first3=Claire|last4=Fuller|first4=Ashley|last5=Kahle|first5=Jason T.|last6=Klenow|first6=Tyler D.|last7=Lewis|first7=Katherine L.|last8=Bradley|first8=Rachel C.|last9=Orriola|first9=John J.|date=2016-09-16|title=Gait Training Interventions for Lower Extremity Amputees: A Systematic Literature Review|journal=Technology and Innovation|volume=18|issue=2–3|pages=99–113|doi=10.21300/18.2-3.2016.99|pmid=28066520|pmc=5218520}}</ref> Using a treadmill, along with the physical therapy treatment, helps the person to experience many of the challenges of walking with a prosthesis.

In the United Kingdom, 75% of lower limb amputations are performed due to inadequate [[Circulatory system|circulation]] (dysvascularity).<ref name=":3">{{Cite journal|last1=Barr|first1=Steven|last2=Howe|first2=Tracey E.|date=2018|title=Prosthetic rehabilitation for older dysvascular people following a unilateral transfemoral amputation|journal=The Cochrane Database of Systematic Reviews|volume=2018|issue=10|article-number=CD005260|doi=10.1002/14651858.CD005260.pub4|issn=1469-493X|pmc=6517199|pmid=30350430}}</ref> This condition is often associated with many other medical conditions ([[Comorbidity|co-morbidities]]) including [[Diabetes mellitus|diabetes]] and [[Cardiovascular disease|heart disease]] that may make it a challenge to recover and use a prosthetic limb to regain mobility and independence.<ref name=":3" /> For people who have inadequate circulation and have lost a lower limb, there is insufficient evidence due to a lack of research, to inform them regarding their choice of prosthetic rehabilitation approaches.<ref name=":3" />
[[File:Replacement surgery - Shoulder total hip and total knee replacement -- Smart-Servier (cropped).jpg|thumb|300px|Types of prosthesis used for replacing joints in the human body]]
Lower extremity prostheses are often categorized by the level of amputation or after the name of a surgeon:<ref>{{Cite book |title=Atlas of limb prosthetics: surgical, prosthetic, and rehabilitation principles |date=2002 |publisher=Mosby Year Book |last1=Bowker|first1=John H.|last2=Michael|first2=John W.|others=American Academy of Orthopaedic Surgeons|isbn=978-0-89203-275-4 |edition= 2nd |location=St. Louis|pages=389, 413, 429, 479, 501, 535, 885 |oclc=54693136}}</ref><ref name=":4">{{Cite book |title=Partial foot amputations |last=Söderberg |first=Bengt |date=2001 |publisher=Centre for Partial Foot Amputees|isbn=978-91-631-0756-6 |edition= 2nd |location=Sweden |page=21 |oclc=152577368}}</ref>

* Transfemoral (Above-knee) 
* Transtibial (Below-knee)
* Ankle disarticulation (more commonly known as Syme's amputation)
* Knee disarticulation ''(also see [[knee replacement]])''
* Hip disarticulation, ''(also see [[hip replacement]])''
* Hemi-pelvictomy
* Partial foot amputations (Pirogoff, Talo-Navicular and Calcaneo-cuboid (Chopart), Tarso-metatarsal (Lisfranc), Trans-metatarsal, Metatarsal-phalangeal, Ray amputations, toe amputations).<ref name=":4" />
* Van Nes rotationplasty

====Prosthetic raw materials====
Prosthetic are made lightweight for better convenience for the amputee. Some of these materials include:
* Plastics:
** Polyethylene
** Polypropylene
** Acrylics
** Polyurethane
* Wood (early prosthetics)
* Rubber (early prosthetics)
* Lightweight metals:

** Aluminum
*Composites:
** Carbon fiber reinforced polymers<ref name="madehow.com"/>

Wheeled prostheses have also been used extensively in the rehabilitation of injured domestic animals, including dogs, cats, pigs, rabbits, and turtles.<ref>{{Cite web|url=https://www.scientificamerican.com/article/animal-prostheses-amazing-menagerie/|title=An Amazing Menagerie of Animal Prostheses|website=[[Scientific American]] |date=March 2013 }}</ref>

=== Organ prostheses ===
Organ prostheses include [[Artificial heart|artificial hearts]], and [[Artificial kidney|artificial kidneys]].

==History==
[[File:Prosthetic toe.jpg|thumb|Prosthetic toe from ancient Egypt, dated between 950-710 BCE.<ref>{{cite journal |last1=Abd Elmohsen |first1=Rehab |title=Earliest prosthetics toes helped Egyptians walk |url=https://www.natureasia.com/en/nmiddleeast/article/10.1038/nmiddleeast.2012.161 |journal=Nature Middle East |date=2012 |language=en |doi=10.1038/nmiddleeast.2012.161}}</ref>]]
Prosthetics originate from the [[ancient Near East]] circa 3000 BCE, with the earliest evidence of prosthetics appearing in [[ancient Egypt]] and [[ancient Iran|Iran]]. The earliest recorded mention of eye prosthetics is from the Egyptian story of the [[Eye of Horus]] dated circa 3000 BC, which involves the left eye of [[Horus]] being plucked out and then restored by [[Thoth]]. Circa 3000-2800 BC, the earliest archaeological evidence of prosthetics is found in ancient Iran, where an eye prosthetic is found buried with a woman in [[Shahr-i Shōkhta]]. It was likely made of bitumen paste that was covered with a thin layer of gold.<ref>{{cite book |last1=Pine |first1=Keith R. |last2=Sloan |first2=Brian H. |last3=Jacobs |first3=Robert J. |title=Clinical Ocular Prosthetics |date=2015 |publisher=Springer |isbn=978-3-319-19057-0 |url=https://books.google.com/books?id=920nCgAAQBAJ&pg=PA283}}</ref> The Egyptians were also early pioneers of foot prosthetics, as shown by the wooden toe found on a body from the [[New Kingdom of Egypt|New Kingdom]] circa 1000 BC.<ref>{{cite web|url=http://www.uh.edu/engines/epi1705.htm |title=No. 1705: A 3000-Year-Old Toe |publisher=Uh.edu |date=2004-08-01 |access-date=2013-03-13}}</ref> Another early textual mention is found in [[South Asia]] circa 1200 BC, involving the warrior queen [[Vishpala]] in the [[Rigveda]].<ref>{{cite journal|url=http://www.acpoc.org/library/1976_05_015.asp|archive-url=https://web.archive.org/web/20071014173159/http://www.acpoc.org/library/1976_05_015.asp|archive-date=2007-10-14|title=A Brief Review of the History of Amputations and Prostheses | author=Vanderwerker, Earl E. Jr. |year= 1976|volume=15|issue=5|journal=ICIB |pages=15–16}}</ref> Roman bronze [[crown (dentistry)|crowns]] have also been found, but their use could have been more aesthetic than medical.<ref>{{cite journal |last1=Rosenfeld |first1=Amnon |last2=Dvorachek |first2=Michael |last3=Rotstein |first3=Ilan |title=Bronze Single Crown-like Prosthetic Restorations of Teeth from the Late Roman Period |journal=Journal of Archaeological Science |date=July 2000 |volume=27 |issue=7 |pages=641–644 |doi=10.1006/jasc.1999.0517|bibcode=2000JArSc..27..641R }}</ref>

An early mention of a prosthetic comes from the Greek historian [[Herodotus]], who tells the story of [[Hegesistratus]], a Greek [[Divination|diviner]] who cut off his own foot to escape his [[Sparta]]n captors and replaced it with a wooden one.<ref>Herodotus, ''The Histories''. 9.37</ref>

=== Wood and metal prosthetics ===
[[File:Roman artificial leg of bronze. Wellcome M0012307.jpg|thumb|upright|left|The Capua leg (replica)]]
[[File:Shengjindian prosthetic leg, 300-200 BCE.jpg|upright=1.5|thumb|A wooden prosthetic leg from [[Shengjindian cemetery]], circa 300 BCE, [[Turpan Museum]]. This is "the oldest functional leg prosthesis known to date".<ref name=LX>{{cite journal |last1=Li |first1=Xiao |last2=Wagner |first2=Mayke |last3=Wu |first3=Xiaohong |last4=Tarasov |first4=Pavel |last5=Zhang |first5=Yongbin |last6=Schmidt |first6=Arno |last7=Goslar |first7=Tomasz |last8=Gresky |first8=Julia |title=Archaeological and palaeopathological study on the third/second century BC grave from Turfan, China: Individual health history and regional implications |journal=Quaternary International |date=21 March 2013 |volume=290-291 |pages=335–343 |doi=10.1016/j.quaint.2012.05.010 |bibcode=2013QuInt.290..335L |issn=1040-6182|quote=Ten radiocarbon dates on the prosthesis, human bones and wood pieces from the same grave suggest the most probable age of the burial is about 300–200 BC (68% confidence interval), thus introducing the oldest functional leg prosthesis known to date.}}</ref>]]
[[File:Eiserne Hand Glasnegativ 6 cropped.jpg|thumb|upright=1.5|Iron prosthetic hand believed to have been owned by Götz von Berlichingen (1480–1562)]]
[[File:Ambroise Pare; prosthetics, mechanical hand Wellcome L0023364.jpg|thumb|upright|"Illustration of mechanical hand", {{Circa|1564}}]]
[[File:Iron artificial arm, 1560-1600. (9663806794).jpg|thumb|Artificial iron hand believed to date from 1560 to 1600]]
[[Pliny the Elder]] also recorded the tale of a Roman general, [[Marcus Sergius]], whose right hand was cut off while campaigning and had an [[Iron hand (prosthesis)|iron hand]] made to hold his shield so that he could return to battle. A famous and quite refined<ref>{{cite web|url=http://www.karlofgermany.com/Goetz.htm |title=The Iron Hand of the Goetz von Berlichingen |publisher=Karlofgermany.com |access-date=2009-11-03}}</ref> historical prosthetic arm was that of [[Götz von Berlichingen]], made at the beginning of the 16th century. The first confirmed use of a prosthetic device, however, is from 950 to 710 BC. In 2000, research pathologists discovered a mummy from this period buried in the Egyptian necropolis near ancient Thebes that possessed an artificial big toe. This toe, consisting of wood and leather, exhibited evidence of use. When reproduced by bio-mechanical engineers in 2011, researchers discovered that this ancient prosthetic enabled its wearer to walk both barefoot and in Egyptian style sandals. Previously, the earliest discovered prosthetic was an artificial [[Roman Capua Leg|leg from Capua]].<ref>{{cite journal |last1=Finch |first1=Jacqueline |title=The ancient origins of prosthetic medicine |journal=The Lancet |date=February 2011 |volume=377 |issue=9765 |pages=548–9 |doi=10.1016/s0140-6736(11)60190-6 |pmid=21341402 |s2cid=42637892 }}</ref>

Around the same time, [[François de la Noue]] is also reported to have had an iron hand, as is, in the 17th century, [[Cavalier de la Salle|René-Robert Cavalier de la Salle]].<ref>{{cite book|date=1887|publisher=S. Low, Marston, Searle & Rivington|place=London|url=https://archive.org/details/shorthistoryofca00bryc |title=A Short History of the Canadian People|author=Bryce, Geore}}</ref> [[Henri de Tonti]] had a prosthetic hook for a hand. During the Middle Ages, prosthetics remained quite basic in form. Debilitated knights would be fitted with prosthetics so they could hold up a shield, grasp a lance or a sword, or stabilize a mounted warrior.<ref>{{cite book|last1=Friedman|first1=Lawrence|title=The Psychological Rehabilitation of the Amputee|date=1978|publisher=Charles C. Thomas|location=Springfield, IL.}}</ref> Only the wealthy could afford anything that would assist in daily life.<ref>{{Cite web |last=Breiding |first=Authors: Dirk H. |title=Arms and Armor—Common Misconceptions and Frequently Asked Questions {{!}} Essay {{!}} The Metropolitan Museum of Art {{!}} Heilbrunn Timeline of Art History |url=https://www.metmuseum.org/toah/hd/aams/hd_aams.htm |access-date=2024-04-15 |website=The Met's Heilbrunn Timeline of Art History |date=October 2004 |language=en}}</ref>

One notable prosthesis was that belonging to an Italian man, who scientists estimate replaced his amputated right hand with a knife.<ref>{{Cite news|url=https://www.sciencealert.com/medieval-lombard-man-amputated-arm-knife-prosthesis|title=This Medieval Italian Man Replaced His Amputated Hand With a Weapon|last=Starr|first=Michelle|work=ScienceAlert|access-date=2018-04-17|language=en-gb}}</ref><ref name=":0">{{cite journal |last1=Micarelli |first1=I |last2=Paine |first2=R |last3=Giostra |first3=C |last4=Tafuri |first4=MA |last5=Profico |first5=A |last6=Boggioni |first6=M |last7=Di Vincenzo |first7=F |last8=Massani |first8=D |last9=Papini |first9=A |last10=Manzi |first10=G |title=Survival to amputation in pre-antibiotic era: a case study from a Longobard necropolis (6th-8th centuries AD) |journal=Journal of Anthropological Sciences |date=31 December 2018 |volume=96 |issue=96 |pages=185–200 |doi=10.4436/JASS.96001 |pmid=29717991 }}</ref> Scientists investigating the skeleton, which was found in a [[Longobard]] cemetery in [[Povegliano Veronese]], estimated that the man had lived sometime between the 6th and 8th centuries AD.<ref name=":1">{{Cite news|url=https://www.forbes.com/sites/kristinakillgrove/2018/04/12/archaeologists-find-ancient-knife-hand-prosthesis-on-medieval-warrior/#1ed6d0339155|title=Archaeologists Find Ancient Knife-Hand Prosthesis on Medieval Warrior|last=Killgrove|first=Kristina|work=Forbes|access-date=2018-04-17|language=en}}</ref><ref name=":0" /> Materials found near the man's body suggest that the knife prosthesis was attached with a leather strap, which he repeatedly tightened with his teeth.<ref name=":1" />

During the Renaissance, prosthetics developed with the use of iron, steel, copper, and wood. Functional prosthetics began to make an appearance in the 1500s.<ref>{{Cite news|url=http://unyq.com/the-history-of-prosthetics/|title=The History of Prosthetics|date=2015-09-21|work=UNYQ|access-date=2018-04-17|language=en-US}}</ref>

=== Technology progress before the 20th century ===
An Italian surgeon recorded the existence of an amputee who had an arm that allowed him to remove his hat, open his purse, and sign his name.<ref>{{cite journal |last1=Romm |first1=Sharon |title=Arms by Design |journal=Plastic and Reconstructive Surgery |date=July 1989 |volume=84 |issue=1 |pages=158–63 |pmid=2660173 |doi=10.1097/00006534-198907000-00029 }}</ref> Improvement in amputation surgery and prosthetic design came at the hands of [[Ambroise Paré]]. Among his inventions was an above-knee device that was a kneeling [[peg leg]] and foot prosthesis with a fixed position, adjustable harness, and knee lock control. The functionality of his advancements showed how future prosthetics could develop.

Other major improvements before the modern era:
* [[Pieter Verduyn]]&nbsp;– First non-locking below-knee (BK) prosthesis.
* [[James Potts]]&nbsp;– Prosthesis made of a wooden shank and socket, a steel knee joint and an articulated foot that was controlled by catgut tendons from the knee to the ankle. Came to be known as "Anglesey Leg" or "Selpho Leg".
* Sir [[James Syme]]&nbsp;– A new method of ankle amputation that did not involve amputating at the thigh.
* [[Benjamin Palmer]]&nbsp;– Improved upon the Selpho leg. Added an anterior spring and concealed tendons to simulate natural-looking movement.
* [[Dubois Parmlee]]&nbsp;– Created prosthetic with a suction socket, polycentric knee, and multi-articulated foot.
* [[Marcel Desoutter]] and [[Charles Desoutter]]&nbsp;– First aluminium prosthesis<ref>{{Cite news| url=http://www.amputee-coalition.org/inmotion/nov_dec_07/history_prosthetics.html | work=inMotion: A Brief History of Prosthetics | title=A Brief History of Prosthetics| date=November–December 2007| access-date=23 November 2010}}</ref>
* Henry Heather Bigg, and his son Henry Robert Heather Bigg, won the Queen's command to provide "surgical appliances" to wounded soldiers after Crimea War. They developed arms that allowed a double arm amputee to crochet, and a hand that felt natural to others based on ivory, felt and leather.<ref>Bigg, Henry Robert Heather (1885) [https://archive.org/details/b22293875 ''Artificial Limbs and the Amputations which Afford the Most Appropriate Stumps in Civil and Military Surgery'']. London</ref>

At the end of World War II, the NAS (National Academy of Sciences) began to advocate better research and development of prosthetics. Through government funding, a research and development program was developed within the Army, Navy, Air Force, and the Veterans Administration.

===Lower extremity modern history===
[[File:A Visit To the Artificial Limbs Factory, Queen Mary's Hospital, Roehampton, November 1941 D5731.jpg|thumbnail|left|An artificial limbs factory in 1941]]
After the Second World War, a team at the [[University of California, Berkeley]] including [[James Foort]] and C.W. Radcliff helped to develop the quadrilateral socket by developing a jig fitting system for amputations above the knee. Socket technology for lower extremity limbs saw a further revolution during the 1980s when John Sabolich C.P.O., invented the Contoured Adducted Trochanteric-Controlled Alignment Method (CATCAM) socket, later to evolve into the Sabolich Socket. He followed the direction of Ivan Long and Ossur Christensen as they developed alternatives to the quadrilateral socket, which in turn followed the open ended plug socket, created from wood.<ref name="Long">{{cite journal |last1=Long |first1=Ivan A. |title=Normal Shape-Normal Alignment (NSNA) Above-Knee Prosthesis |via= O&P Virtual Library |journal=Clinical Prosthetics & Orthotics |year=1985 |volume=9 |issue=4 |pages=9–14 |url=http://www.oandplibrary.org/cpo/1985_04_009.asp }}</ref> The advancement was due to the difference in the socket to patient contact model. Prior to this, sockets were made in the shape of a square shape with no specialized containment for muscular tissue. New designs thus help to lock in the bony anatomy, locking it into place and distributing the weight evenly over the existing limb as well as the musculature of the patient. Ischial containment is well known and used today by many prosthetist to help in patient care. Variations of the ischial containment socket thus exists and each socket is tailored to the specific needs of the patient. Others who contributed to socket development and changes over the years include Tim Staats, Chris Hoyt, and Frank Gottschalk. Gottschalk disputed the efficacy of the CAT-CAM socket- insisting the surgical procedure done by the amputation surgeon was most important to prepare the amputee for good use of a prosthesis of any type socket design.<ref name="Gottschalk-Kourosh-Stills">{{cite journal |last1=Gottschalk |first1=Frank A. |last2=Kourosh |first2=Sohrab |last3=Stills |first3=Melvin |last4=McClellan |first4=Bruce |last5=Roberts |first5=Jim |title=Does Socket Configuration Influence the Position of the Femur in Above-Knee Amputation? |journal=Journal of Prosthetics and Orthotics |date=October 1989 |volume=2 |issue=1 |page=94 |doi=10.1097/00008526-198910000-00009 }}</ref>

The first microprocessor-controlled prosthetic knees became available in the early 1990s. The Intelligent Prosthesis was the first commercially available microprocessor-controlled prosthetic knee. It was released by Chas. A. Blatchford & Sons, Ltd., of Great Britain, in 1993 and made walking with the prosthesis feel and look more natural.<ref>[http://www.blatchford.co.uk/about/company-history/ "Blatchford Company History"], Blatchford Group.</ref> An improved version was released in 1995 by the name Intelligent Prosthesis Plus. Blatchford released another prosthesis, the Adaptive Prosthesis, in 1998. The Adaptive Prosthesis utilized hydraulic controls, pneumatic controls, and a microprocessor to provide the amputee with a gait that was more responsive to changes in walking speed. Cost analysis reveals that a sophisticated above-knee prosthesis will be about $1&nbsp;million in 45 years, given only annual cost of living adjustments.<ref name=PikeAlvin/>

In 2019, a project under AT2030 was launched in which bespoke sockets are made using a thermoplastic, rather than through a plaster cast. This is faster to do and significantly less expensive. The sockets were called Amparo Confidence sockets.<ref>{{cite web |last1=Barbareschi |first1=Giulia |title=One small step for an amputee and a giant leap for Amparo and GDI Hub |url=https://www.disabilityinnovation.com/blog/one-small-step-for-an-amputee-and-a-giant-leap-for-amparo-and-gdi-hub |website=Global Disability Innovation Hub |archive-url=https://web.archive.org/web/20201124123015/https://www.disabilityinnovation.com/blog/one-small-step-for-an-amputee-and-a-giant-leap-for-amparo-and-gdi-hub |archive-date=24 November 2020 |language=en |date=30 July 2019 |url-status=live}}</ref><ref>{{cite web |title=Changing Prosthetic Service Delivery with Amparo |url=https://www.disabilityinnovation.com/projects/changing-prosthetic-service-delivery-with-amparo |website=Global Disability Innovation Hub |archive-url=https://web.archive.org/web/20220517073957/https://www.disabilityinnovation.com/projects/changing-prosthetic-service-delivery-with-amparo |archive-date=17 May 2022}}</ref>

===Upper extremity modern history===
[[File:DARPA 2006b RP 619x316.jpg|thumb|DARPA Revolutionizing Prosthetics - The LUKE Arm]]
In 2005, [[DARPA]] started the Revolutionizing Prosthetics program.<ref>{{cite journal |first1=Matthew S. |last1=Johannes |first2=John D. |last2=Bigelow |first3=James M. |last3=Burck |first4=Stuart D. |last4=Harshbarger |first5=Matthew V. |last5=Kozlowski |first6=Thomas |last6=Van Doren |url=http://www.jhuapl.edu/techdigest/TD/td3003/30_3-Johannes.pdf |title=An Overview of the Developmental Process for the Modular Prosthetic Limb |journal=Johns Hopkins APL Technical Digest |volume=30 |issue=3 |year=2011 |pages=207–16 |access-date=2017-10-05 |archive-date=2017-09-19 |archive-url=https://web.archive.org/web/20170919024845/http://www.jhuapl.edu/techdigest/TD/td3003/30_3-Johannes.pdf }}</ref><ref>{{cite journal |last1=Adee |first1=Sally |title=The revolution will be prosthetized |journal=IEEE Spectrum |date=January 2009 |volume=46 |issue=1 |pages=44–8 |url=https://spectrum.ieee.org/winner-the-revolution-will-be-prosthetized |doi=10.1109/MSPEC.2009.4734314 |s2cid=34235585 |url-access=subscription }}</ref><ref>{{cite journal |first1=James M. |last1=Burck |first2=John D. |last2=Bigelow |first3=Stuart D. |last3=Harshbarger |title=Revolutionizing Prosthetics: Systems Engineering Challenges and Opportunities |journal=Johns Hopkins APL Technical Digest |volume=30 |issue=3 |year=2011 |pages=186–97 |citeseerx=10.1.1.685.6772}}</ref><ref>{{cite journal |last1=Bogue |first1=Robert |title=Exoskeletons and robotic prosthetics: a review of recent developments |journal=Industrial Robot |date=21 August 2009 |volume=36 |issue=5 |pages=421–427 |doi=10.1108/01439910910980141 }}</ref><ref>{{cite journal |last1=Miranda |first1=Robbin A. |last2=Casebeer |first2=William D. |last3=Hein |first3=Amy M. |last4=Judy |first4=Jack W. |last5=Krotkov |first5=Eric P. |last6=Laabs |first6=Tracy L. |last7=Manzo |first7=Justin E. |last8=Pankratz |first8=Kent G. |last9=Pratt |first9=Gill A. |last10=Sanchez |first10=Justin C. |last11=Weber |first11=Douglas J. |last12=Wheeler |first12=Tracey L. |last13=Ling |first13=Geoffrey S.F. |title=DARPA-funded efforts in the development of novel brain–computer interface technologies |journal=Journal of Neuroscience Methods |date=April 2015 |volume=244 |pages=52–67 |doi=10.1016/j.jneumeth.2014.07.019 |pmid=25107852 |s2cid=14678623 |doi-access=free }}</ref><ref>{{cite web |title=The Pentagon's Bionic Arm |date=10 April 2009 |url=http://www.cbsnews.com/news/the-pentagons-bionic-arm/ |publisher=CBS News |access-date=9 May 2015 }}</ref> According to DARPA, the goal of the $100 million program was to "develop an advanced electromechanical prosthetic upper limb with near-natural control that would dramatically enhance independence and quality of life for amputees."<ref>{{Cite web |title=Revolutionizing Prosthetics |url=https://www.darpa.mil/about-us/timeline/revolutionizing-prosthetics |access-date=June 4, 2024 |website=darpa.mil|archive-url=https://web.archive.org/web/20200808031913/https://www.darpa.mil/about-us/timeline/revolutionizing-prosthetics|archive-date=8 August 2020}}</ref><ref name=":9">{{Cite web |title=Dean Kamen's "Luke Arm" Prosthesis Receives FDA Approval - IEEE Spectrum |url=https://spectrum.ieee.org/dean-kamen-luke-arm-prosthesis-receives-fda-approval |access-date=2024-06-04 |website=[[IEEE]] |language=en| first1=Guizzo| last1=Erico|date=2014-05-14 }}</ref>  In 2014, the LUKE Arm developed by [[Dean Kamen]] and his team at [[DEKA (company)|DEKA Research and Development Corp.]] became the first prosthetic arm approved by [[Food and Drug Administration|FDA]] that "translates signals from a person's muscles to perform complex tasks," according to FDA.<ref name=":9" /><ref>{{Cite web |title=Winner: The Revolution Will Be Prosthetized - IEEE Spectrum |url=https://spectrum.ieee.org/winner-the-revolution-will-be-prosthetized |access-date=2024-06-04|first1= Sally|last1=Adee|date= 2009-01-01 |website=[[IEEE]] |language=en}}</ref> [[Johns Hopkins University]] and the [[United States Department of Veterans Affairs|U.S. Department of Veteran Affairs]] also participated in the program.<ref name=":9" /><ref>{{Cite web |title=The LUKE/DEKA advanced prosthetic arm |url=https://www.research.va.gov/research_in_action/The-LUKE-DEKA-advanced-prosthetic-arm.cfm |access-date=2024-06-04 |website=www.research.va.gov|date= 2018-08-01}}</ref>

=== Design trends moving forward ===
There are many steps in the evolution of prosthetic design trends that are moving forward with time. Many design trends point to lighter, more durable, and flexible materials like carbon fiber, silicone, and advanced polymers. These not only make the prosthetic limb lighter and more durable but also allow it to mimic the look and feel of natural skin, providing users with a more comfortable and natural experience.<ref name=":7">{{Cite web |last= |first= |date=September 28, 2023 |title=The Evolution of Prosthetic Limbs: Current Technological Advancements |url=https://www.premierprosthetic.com/09/the-evolution-of-prosthetic-limbs-current-technological-advancements/ |access-date=2023-11-27 |website=premierprosthetic.com |language=en-US}}</ref> This new technology helps prosthetic users blend in with people with normal ligaments to reduce the stigmatism for people who wear prosthetics. Another trend points towards using [[bionics]] and myoelectric components in prosthetic design. These limbs utilize sensors to detect electrical signals from the user's residual muscles. The signals are then converted into motions, allowing users to control their prosthetic limbs using their own muscle contractions. This has greatly improved the range and fluidity of movements available to amputees, making tasks like grasping objects or walking naturally much more feasible.<ref name=":7" /> Integration with AI is also on the forefront to the prosthetic design. AI-enabled prosthetic limbs can learn and adapt to the user's habits and preferences over time, ensuring optimal functionality. By analyzing the user's gait, grip, and other movements, these smart limbs can make real-time adjustments, providing smoother and more natural motions.<ref name=":7" />

==Patient procedure==
A prosthesis is a functional replacement for an amputated or congenitally malformed or missing limb. [[Prosthetist]]s are responsible for the prescription, design, and management of a prosthetic device.

In most cases, the prosthetist begins by taking a plaster cast of the patient's affected limb. Lightweight, high-strength thermoplastics are custom-formed to this model of the patient. Cutting-edge materials such as carbon fiber, titanium and Kevlar provide strength and durability while making the new prosthesis lighter. More sophisticated prostheses are equipped with advanced electronics, providing additional stability and control.<ref>{{cite web |url=http://www.progoandp.com/services/prosthetics/ |title=Custom Prosthetics, Artificial Limbs LI, NY &#124; Progressive O&P |publisher=Progoandp.com |access-date=2016-12-28}}</ref>

==Current technology and manufacturing==
[[File:WorkNC-Knee prosthesis.jpg|right|thumb|Knee prosthesis manufactured using [[WorkNC]] [[Computer Aided Manufacturing]] software]]
Over the years, there have been advancements in artificial limbs. New plastics and other materials, such as [[carbon fiber]], have allowed artificial limbs to be stronger and lighter, limiting the amount of extra energy necessary to operate the limb. This is especially important for trans-femoral amputees. Additional materials have allowed artificial limbs to look much more realistic, which is important to trans-radial and transhumeral amputees because they are more likely to have the artificial limb exposed.<ref name="three">{{cite web|url=http://www.madehow.com/Volume-1/Artificial-Limb.html |title=How artificial limb is made&nbsp;– Background, Raw materials, The manufacturing process of artificial limb, Physical therapy, Quality control |publisher=Madehow.com |date=1988-04-04 |access-date=2010-10-03}}</ref>
[[File:Journal.pone.0019508.g004 prosthetic finger.png|left|thumb|Manufacturing a prosthetic finger]]

In addition to new materials, the use of electronics has become very common in artificial limbs. Myoelectric limbs, which control the limbs by converting muscle movements to electrical signals, have become much more common than cable operated limbs. Myoelectric signals are picked up by electrodes, the signal gets integrated and once it exceeds a certain threshold, the prosthetic limb control signal is triggered which is why inherently, all myoelectric controls lag. Conversely, cable control is immediate and physical, and through that offers a certain degree of direct force feedback that myoelectric control does not. Computers are also used extensively in the manufacturing of limbs. [[CAD/CAM|Computer Aided Design and Computer Aided Manufacturing]] are often used to assist in the design and manufacture of artificial limbs.<ref name="three" /><ref name="sapphire">{{cite journal |last1=Mamalis |first1=AG |last2=Ramsden |first2=JJ |last3=Grabchenko |first3=AI |last4=Lytvynov |first4=LA |last5=Filipenko |first5=VA |last6=Lavrynenko |first6=SN |title=A novel concept for the manufacture of individual sapphire-metallic hip joint endoprostheses |journal=Journal of Biological Physics and Chemistry |date=2006 |volume=6 |issue=3 |pages=113–117 |doi=10.4024/30601.jbpc.06.03|hdl=1826/2527 |hdl-access=free }}</ref>

Most modern artificial limbs are attached to the residual limb (stump) of the amputee by belts and cuffs or by [[suction]]. The residual limb either directly fits into a socket on the prosthetic, or—more commonly today—a liner is used that then is fixed to the socket either by vacuum (suction sockets) or a pin lock. Liners are soft and by that, they can create a far better suction fit than hard sockets. Silicone liners can be obtained in standard sizes, mostly with a circular (round) cross section, but for any other residual limb shape, custom liners can be made. The socket is custom made to fit the residual limb and to distribute the forces of the artificial limb across the area of the residual limb (rather than just one small spot), which helps reduce wear on the residual limb.

=== Production of prosthetic socket ===
The production of a prosthetic socket begins with capturing the geometry of the residual limb; this process is called shape capture. The goal of this process is to create an accurate representation of the residual limb, which is critical to achieve good socket fit.<ref name=":6">{{Cite journal|last1=Suyi Yang|first1=Eddie|last2=Aslani|first2=Navid|last3=McGarry|first3=Anthony|date=October 2019|title=Influences and trends of various shape-capture methods on outcomes in trans-tibial prosthetics: A systematic review|journal=Prosthetics and Orthotics International|volume=43|issue=5|pages=540–555|doi=10.1177/0309364619865424|issn=1746-1553|pmid=31364475|s2cid=198999869}}</ref> The custom socket is created by taking a plaster cast of the residual limb or, more commonly today, of the liner worn over their residual limb, and then making a mold from the plaster cast. The commonly used compound is called Plaster of Paris.<ref>{{Cite journal|last1=Sharma|first1=Hemant|last2=Prabu|first2=Dhanasekara|date=September 2013|title=Plaster of Paris: Past, present and future|journal=Journal of Clinical Orthopaedics and Trauma|volume=4|issue=3|pages=107–109|doi=10.1016/j.jcot.2013.09.004|issn=0976-5662|pmc=3880430|pmid=26403547}}</ref> In recent years, various digital shape capture systems have been developed which can be input directly to a computer allowing for a more sophisticated design. In general, the shape capturing process begins with the digital acquisition of three-dimensional (3D) geometric data from the amputee's residual limb. Data are acquired with either a probe, laser scanner, structured light scanner, or a photographic-based 3D scanning system.<ref>{{Cite journal|last1=Herbert|first1=Nicholas|last2=Simpson|first2=David|last3=Spence|first3=William D.|last4=Ion|first4=William|date=March 2005|title=A preliminary investigation into the development of 3-D printing of prosthetic sockets|journal=Journal of Rehabilitation Research and Development|volume=42|issue=2|pages=141–146|doi=10.1682/jrrd.2004.08.0134|doi-broken-date=12 July 2025 |issn=1938-1352|pmid=15944878|s2cid=9385882 }}</ref>

After shape capture, the second phase of the socket production is called rectification, which is the process of modifying the model of the residual limb by adding volume to bony prominence and potential pressure points and remove volume from load bearing area. This can be done manually by adding or removing plaster to the positive model, or virtually by manipulating the computerized model in the software.<ref>{{Cite journal|last1=Sewell|first1=P.|last2=Noroozi|first2=S.|last3=Vinney|first3=J.|last4=Andrews|first4=S.|date=August 2000|title=Developments in the trans-tibial prosthetic socket fitting process: a review of past and present research|journal=Prosthetics and Orthotics International|volume=24|issue=2|pages=97–107|doi=10.1080/03093640008726532|issn=0309-3646|pmid=11061196|s2cid=20147798}}</ref> Lastly, the fabrication of the prosthetic socket begins once the model has been rectified and finalized. The prosthetists would wrap the positive model with a semi-molten plastic sheet or carbon fiber coated with epoxy resin to construct the prosthetic socket.<ref name=":6" /> For the computerized model, it can be 3D printed using a various of material with different flexibility and mechanical strength.<ref>{{Cite journal|last1=Ribeiro|first1=Danielle|last2=Cimino|first2=Stephanie R.|last3=Mayo|first3=Amanda L.|last4=Ratto|first4=Matt|last5=Hitzig|first5=Sander L.|date=2019-08-16|title=3D printing and amputation: a scoping review|journal=Disability & Rehabilitation: Assistive Technology|volume=16|issue=2|pages=221–240|doi=10.1080/17483107.2019.1646825|issn=1748-3115|pmid=31418306|s2cid=201018681}}</ref>

Optimal socket fit between the residual limb and socket is critical to the function and usage of the entire prosthesis. If the fit between the residual limb and socket attachment is too loose, this will reduce the area of contact between the residual limb and socket or liner, and increase pockets between residual limb skin and socket or liner. Pressure then is higher, which can be painful. Air pockets can allow sweat to accumulate that can soften the skin. Ultimately, this is a frequent cause for itchy skin rashes. Over time, this can lead to breakdown of the skin.<ref name="four">{{cite web|url=http://www.abc.net.au/science/slab/leg/default.htm |title=Getting an artificial leg up&nbsp;– Cathy Johnson |publisher=Australian Broadcasting Corporation |access-date=2010-10-03 }}</ref> On the other hand, a very tight fit may excessively increase the interface pressures that may also lead to skin breakdown after prolonged use.<ref>{{Cite journal|last1=Mak|first1=A. F.|last2=Zhang|first2=M.|last3=Boone|first3=D. A.|date=March 2001|title=State-of-the-art research in lower-limb prosthetic biomechanics-socket interface: a review|journal=Journal of Rehabilitation Research and Development|volume=38|issue=2|pages=161–174|issn=0748-7711|pmid=11392649}}</ref>

Artificial limbs are typically manufactured using the following steps:<ref name="three" />
# Measurement of the residual limb
# Measurement of the body to determine the size required for the artificial limb
# Fitting of a silicone liner
# Creation of a model of the liner worn over the residual limb
# Formation of [[thermoplastic]] sheet around the model&nbsp;– This is then used to test the fit of the prosthetic
# Formation of permanent socket
# Formation of plastic parts of the artificial limb&nbsp;– Different methods are used, including [[vacuum forming]] and [[injection molding]]
# Creation of metal parts of the artificial limb using [[die casting]]
# Assembly of entire limb

===Body-powered arms===

Current technology allows body-powered arms to weigh around one-half to one-third of what a myoelectric arm does.

====Sockets====
Current body-powered arms contain sockets that are built from hard epoxy or carbon fiber. These sockets or "interfaces" can be made more comfortable by lining them with a softer, compressible foam material that provides padding for the bone prominences. A self-suspending or supra-condylar socket design is useful for those with short to mid-range below elbow absence. Longer limbs may require the use of a locking roll-on type inner liner or more complex harnessing to help augment suspension.

====Wrists====
Wrist units are either screw-on connectors featuring the UNF 1/2-20 thread (USA) or quick-release connector, of which there are different models.

====Voluntary opening and voluntary closing====
Two types of body-powered systems exist, voluntary opening "pull to open" and voluntary closing "pull to close". Virtually all "split hook" prostheses operate with a voluntary opening type system.

More modern "prehensors" called GRIPS utilize voluntary closing systems. The differences are significant. Users of voluntary opening systems rely on elastic bands or springs for gripping force, while users of voluntary closing systems rely on their own body power and energy to create gripping force.

Voluntary closing users can generate prehension forces equivalent to the normal hand, up to or exceeding one hundred pounds. Voluntary closing GRIPS require constant tension to grip, like a human hand, and in that property, they do come closer to matching human hand performance. Voluntary opening split hook users are limited to forces their rubber or springs can generate which usually is below 20 pounds.

====Feedback====
An additional difference exists in the biofeedback created that allows the user to "feel" what is being held. Voluntary opening systems once engaged provide the holding force so that they operate like a passive vice at the end of the arm. No gripping feedback is provided once the hook has closed around the object being held. Voluntary closing systems provide directly [[Proportional Myoelectric Control|proportional control]] and biofeedback so that the user can feel how much force that they are applying.

In 1997, the [[Colombians|Colombian]] Prof. [[Álvaro Ríos Poveda]], a researcher in bionics in [[Latin America]], developed an upper limb and hand prosthesis with [[sensory feedback]]. This technology allows amputee patients to handle prosthetic hand systems in a more natural way.<ref>{{Cite book|last=Rios Poveda|first=Alvaro|url=https://dukespace.lib.duke.edu/dspace/handle/10161/2661|title=Myoelectric Prostheses with Sensorial Feedback|date=2002|publisher=Myoelectric Symposium|isbn=978-1-55131-029-9|language=en-US}}</ref>

A recent study showed that by stimulating the median and ulnar nerves, according to the information provided by the artificial sensors from a hand prosthesis, physiologically appropriate (near-natural) sensory information could be provided to an amputee. This feedback enabled the participant to effectively modulate the grasping force of the prosthesis with no visual or auditory feedback.<ref name="pmid 24500407">{{cite journal|s2cid=206682721 |display-authors=6|last1=Raspopovic |first1=Stanisa |last2=Capogrosso |first2=Marco |last3=Petrini |first3=Francesco Maria |last4=Bonizzato |first4=Marco |last5=Rigosa |first5=Jacopo |last6=Di Pino |first6=Giovanni |last7=Carpaneto |first7=Jacopo |last8=Controzzi |first8=Marco |last9=Boretius |first9=Tim |last10=Fernandez |first10=Eduardo |last11=Granata |first11=Giuseppe |last12=Oddo |first12=Calogero Maria |last13=Citi |first13=Luca |last14=Ciancio |first14=Anna Lisa |last15=Cipriani |first15=Christian |last16=Carrozza |first16=Maria Chiara |last17=Jensen |first17=Winnie |last18=Guglielmelli |first18=Eugenio |last19=Stieglitz |first19=Thomas |last20=Rossini |first20=Paolo Maria |last21=Micera |first21=Silvestro |title=Restoring Natural Sensory Feedback in Real-Time Bidirectional Hand Prostheses |journal=Science Translational Medicine |date=5 February 2014 |volume=6 |issue=222 |pages=222ra19|pmid=24500407 |doi=10.1126/scitranslmed.3006820|url=http://infoscience.epfl.ch/record/198047}}</ref>

In February 2013, researchers from [[École Polytechnique Fédérale de Lausanne]] in Switzerland and the [[Sant'Anna School of Advanced Studies|Scuola Superiore Sant'Anna]] in Italy, implanted electrodes into an amputee's arm, which gave the patient sensory feedback and allowed for real time control of the prosthetic.<ref>{{cite news |last1=Bowerman |first1=Mary |title=Bionic hand allows amputee to feel again |url=https://www.usatoday.com/story/news/nation/2014/02/05/bionic-hand-amputee-feels/5229665/ |work=USA Today |date=2014-02-05 |quote=With a new prosthetic, researchers have managed to restore the sense of touch for a Denmark man who lost his left hand nine years ago.}}</ref> With wires linked to nerves in his upper arm, the Danish patient was able to handle objects and instantly receive a sense of touch through the special artificial hand that was created by Silvestro Micera and researchers both in Switzerland and Italy.<ref>{{cite news |title=Artificial hand offering immediate touch response a success |url=http://www.channelnewsasia.com/news/health/artificial-hand-offering/986332.html |work=NewsAsia |date=2014-02-07 |archive-url=https://web.archive.org/web/20140409134748/https://www.channelnewsasia.com/news/health/artificial-hand-offering/986332.html |archive-date=2014-04-09}}</ref>

In July 2019, this technology was expanded on even further by researchers from the [[University of Utah]], led by Jacob George. The group of researchers implanted electrodes into the patient's arm to map out several sensory precepts. They would then stimulate each electrode to figure out how each sensory precept was triggered, then proceed to map the sensory information onto the prosthetic. This would allow the researchers to get a good approximation of the same kind of information that the patient would receive from their natural hand. Unfortunately, the arm is too expensive for the average user to acquire, however, Jacob mentioned that insurance companies could cover the costs of the prosthetic.<ref>{{Cite web|last=DelViscio|first=Jeffery|title=A Robot Hand Helps Amputees "Feel" Again|url=https://www.scientificamerican.com/article/a-robot-hand-helps-amputees-feel-again/|access-date=2020-06-12|website=Scientific American|language=en|date=2019-07-24}}</ref>

====Terminal devices====
Terminal devices contain a range of hooks, prehensors, hands or other devices.

=====Hooks=====
Voluntary opening split hook systems are simple, convenient, light, robust, versatile and relatively affordable.

A hook does not match a normal human hand for appearance or overall versatility, but its material tolerances can exceed and surpass the normal human hand for mechanical stress (one can even use a hook to slice open boxes or as a hammer whereas the same is not possible with a normal hand), for thermal stability (one can use a hook to grip items from boiling water, to turn meat on a grill, to hold a match until it has burned down completely) and for chemical hazards (as a metal hook withstands acids or lye, and does not react to solvents like a prosthetic glove or human skin).

=====Hands=====
[[File:Myoelectric prosthetic arm.jpg|right|thumb|Actor [[Owen Wilson]] gripping the myoelectric prosthetic arm of a United States Marine]]

Prosthetic hands are available in both voluntary opening and voluntary closing versions and because of their more complex mechanics and cosmetic glove covering require a relatively large activation force, which, depending on the type of harness used, may be uncomfortable.<ref>{{Cite journal
  |vauthors=Smit G, Plettenburg DH | title = Efficiency of Voluntary Closing Hand and Hook Prostheses
  | journal = Prosthetics and Orthotics International
  | volume = 34
  | issue = 4
  | pages = 411–427
  | year = 2010
  | doi = 10.3109/03093646.2010.486390
  | pmid = 20849359| s2cid = 22327910
 | url = http://repository.tudelft.nl/islandora/object/uuid%3A8c18e55f-842a-4a74-9b62-4b7fd23d9756/datastream/OBJ/view
  }}</ref> A recent study by the Delft University of Technology, The Netherlands, showed that the development of mechanical prosthetic hands has been neglected during the past decades. The study showed that the pinch force level of most current mechanical hands is too low for practical use.<ref>{{cite journal|last1=Smit|first1=G|last2=Bongers|first2=RM|last3=Van der Sluis|first3=CK|last4=Plettenburg|first4=DH|title=Efficiency of voluntary opening hand and hook prosthetic devices: 24 years of development?|journal=Journal of Rehabilitation Research and Development|date=2012|volume=49|issue=4|pages=523–534|doi=10.1682/JRRD.2011.07.0125|pmid=22773256|url=https://research.rug.nl/en/publications/f11785ef-3165-44f2-8c5c-8aa0415aedab}}</ref> The best tested hand was a prosthetic hand developed around 1945. In 2017 however, a research has been started with bionic hands by [[Laura Hruby]] of the [[Medical University of Vienna]].<ref>{{cite magazine |last1=Robitzski |first1=Dan|orig-date=First published 18 April 2017 as "A Spare Hand" |title= Disabled Hands Successfully Replaced with Bionic Prosthetics|magazine=Scientific American |date=May 2017 |volume=316 |issue=5 |page=17 |doi=10.1038/scientificamerican0517-17}}</ref><ref>{{cite journal |last1=Hruby |first1=Laura A. |last2=Sturma |first2=Agnes |last3=Mayer |first3=Johannes A. |last4=Pittermann |first4=Anna |last5=Salminger |first5=Stefan |last6=Aszmann |first6=Oskar C. |title=Algorithm for bionic hand reconstruction in patients with global brachial plexopathies |journal=Journal of Neurosurgery |date=November 2017 |volume=127 |issue=5 |pages=1163–1171 |doi=10.3171/2016.6.JNS16154|pmid=28093018 |s2cid=28143731 }}</ref> A few open-hardware 3-D printable bionic hands have also become available.<ref>[https://bionico.org/mains-low-cost/ 3D bionic hands]</ref> Some companies are also producing robotic hands with integrated forearm, for fitting unto a patient's upper arm<ref>{{cite news |title=UK woman can ride bike for first time with 'world's most lifelike bionic hand' |url=https://www.theguardian.com/uk-news/2015/jun/16/uk-woman-ride-bike-first-time-worlds-most-lifelike-bionic-hand |work=[[The Guardian]] |date=2015-06-16}}</ref><ref>{{cite news |last1=Bagot |first1=Martin |title=Revolutionary £1m bionic hand lets one-armed woman do everyday tasks |url=https://www.mirror.co.uk/news/technology-science/technology/revolutionary-1m-bionic-hand-allows-5895366 |work=Daily Mirror |date=2015-06-16 |language=en}}</ref> and in 2020, at the Italian Institute of Technology (IIT), another robotic hand with integrated forearm (Soft Hand Pro) was developed.<ref>{{cite news |last1=Rosmino |first1=Claudio |title=Light, lifelike and affordable: EU researchers develop innovative bionic hand |url=https://www.euronews.com/next/2020/03/02/a-helping-hand-eu-researchers-develop-bionic-hand-that-imitates-life |work=Euronews |date=2 March 2020}}</ref>

====Commercial providers and materials====
Hosmer and [[Otto Bock]] are major commercial hook providers. Mechanical hands are sold by Hosmer and Otto Bock as well; the Becker Hand is still manufactured by the Becker family. Prosthetic hands may be fitted with standard stock or custom-made cosmetic looking silicone gloves. But regular work gloves may be worn as well. Other terminal devices include the V2P Prehensor, a versatile robust gripper that allows customers to modify aspects of it, Texas Assist Devices (with a whole assortment of tools) and TRS that offers a range of terminal devices for sports. Cable harnesses can be built using aircraft steel cables, ball hinges, and self-lubricating cable sheaths. Some prosthetics have been designed specifically for use in salt water.<ref>{{cite web|last1=Onken|first1=Sarah|title=Dive In|url=http://www.cityviewnc.com/2014/01/06/20010/dive-in|website=cityviewnc.com|access-date=24 August 2015|archive-url=https://web.archive.org/web/20150910011729/http://www.cityviewnc.com/2014/01/06/20010/dive-in|archive-date=10 September 2015|df=dmy-all}}</ref>

===Lower-extremity prosthetics===
[[File:AustralianParalympianOfTheYear 468.JPG|thumb|right|A prosthetic leg worn by [[Ellie Cole]]]]
Lower-extremity prosthetics describes artificially replaced limbs located at the hip level or lower. Concerning all ages Ephraim et al. (2003) found a worldwide estimate of all-cause lower-extremity amputations of 2.0–5.9 per 10,000 inhabitants. For birth prevalence rates of congenital limb deficiency they found an estimate between 3.5 and 7.1 cases per 10,000 births.<ref>{{cite journal|pmid=12736892|year=2003|last1=Ephraim|first1=P. L.|title=Epidemiology of limb loss and congenital limb deficiency: A review of the literature|journal=Archives of Physical Medicine and Rehabilitation|volume=84|issue=5|pages=747–61|last2=Dillingham|first2=T. R.|last3=Sector|first3=M|last4=Pezzin|first4=L. E.|last5=MacKenzie|first5=E. J.|doi=10.1016/S0003-9993(02)04932-8}}</ref>

The two main subcategories of lower extremity prosthetic devices are trans-tibial (any amputation transecting the tibia bone or a congenital anomaly resulting in a tibial deficiency), and trans-femoral (any amputation transecting the femur bone or a congenital anomaly resulting in a femoral deficiency). In the prosthetic industry, a trans-tibial prosthetic leg is often referred to as a "BK" or below the knee prosthesis while the trans-femoral prosthetic leg is often referred to as an "AK" or above the knee prosthesis.

Other, less prevalent lower extremity cases include the following:
# Hip disarticulations&nbsp;– This usually refers to when an amputee or congenitally challenged patient has either an amputation or anomaly at or in close proximity to the hip joint. ''See [[hip replacement]]''
# Knee disarticulations&nbsp;– This usually refers to an amputation through the knee disarticulating the femur from the tibia. ''See [[knee replacement]]''
# Symes&nbsp;– This is an ankle disarticulation while preserving the heel pad.

====Socket====
The socket serves as an interface between the residuum and the prosthesis, ideally allowing comfortable weight-bearing, movement control and [[proprioception]].<ref>{{cite journal|pmid=11392649|year=2001|last1=Mak|first1=A. F.|title=State-of-the-art research in lower-limb prosthetic biomechanics-socket interface: A review|journal=Journal of Rehabilitation Research and Development|volume=38|issue=2|pages=161–74|last2=Zhang|first2=M|last3=Boone|first3=D. A.}}</ref> Socket problems, such as discomfort and skin breakdown, are rated among the most important issues faced by lower-limb amputees.<ref>{{cite journal |last1=Legro |first1=MW |last2=Reiber |first2=G |last3=del Aguila |first3=M |last4=Ajax |first4=MJ |last5=Boone |first5=DA |last6=Larsen |first6=JA |last7=Smith |first7=DG |last8=Sangeorzan |first8=B |title=Issues of importance reported by persons with lower limb amputations and prostheses. |journal=Journal of Rehabilitation Research and Development |date=July 1999 |volume=36 |issue=3 |pages=155–63 |pmid=10659798 }}</ref>

====Shank and connectors====
This part creates distance and support between the knee-joint and the foot (in case of an upper-leg prosthesis) or between the socket and the foot. The type of connectors that are used between the shank and the knee/foot determines whether the prosthesis is modular or not. Modular means that the angle and the displacement of the foot in respect to the socket can be changed after fitting. In developing countries prosthesis mostly are non-modular, in order to reduce cost. When considering children modularity of angle and height is important because of their average growth of 1.9&nbsp;cm annually.<ref name="ReferenceA"/>

====Foot====
Providing contact to the ground, the foot provides shock absorption and stability during stance.<ref>{{cite journal|doi=10.1097/00008526-200510001-00007|title=Perspectives on How and Why Feet are Prescribed|journal=Journal of Prosthetics and Orthotics|volume=17|pages=S18–S22|year=2005|last1=Stark|first1=Gerald}}</ref> Additionally it influences gait biomechanics by its shape and stiffness. This is because the trajectory of the center of pressure (COP) and the angle of the ground reaction forces is determined by the shape and stiffness of the foot and needs to match the subject's build in order to produce a normal gait pattern.<ref>{{cite journal|doi=10.1016/0966-6362(93)90038-3|title=Trajectory of the body COG and COP during initiation and termination of gait|journal=Gait & Posture|volume=1|pages=9–22|year=1993|last1=Jian|first1=Yuancheng|last2=Winter|first2=DA|last3=Ishac|first3=MG|last4=Gilchrist|first4=L}}</ref> Andrysek (2010) found 16 different types of feet, with greatly varying results concerning durability and biomechanics. The main problem found in current feet is durability, endurance ranging from 16 to 32 months<ref name="ReferenceB">{{cite journal |last1=Andrysek |first1=Jan |title=Lower-limb prosthetic technologies in the developing world: A review of literature from 1994–2010 |journal=Prosthetics and Orthotics International |date=December 2010 |volume=34 |issue=4 |pages=378–398 |doi=10.3109/03093646.2010.520060 |pmid=21083505 |s2cid=27233705 }}</ref> These results are for adults and will probably be worse for children due to higher activity levels and scale effects. Evidence comparing different types of feet and ankle prosthetic devices is not strong enough to determine if one mechanism of ankle/foot is superior to another.<ref name=":2">{{cite journal |last1=Hofstad |first1=Cheriel J |last2=van der Linde |first2=Harmen |last3=van Limbeek |first3=Jacques |last4=Postema |first4=Klaas |title=Prescription of prosthetic ankle-foot mechanisms after lower limb amputation |journal=Cochrane Database of Systematic Reviews |issue=1 |article-number=CD003978 |date=26 January 2004 |volume=2010 |doi=10.1002/14651858.CD003978.pub2 |pmid=14974050 |pmc=8762647 |url=https://pure.rug.nl/ws/files/67438636/Hofstad_et_al_2004_Cochrane_Database_of_Systematic_Reviews.pdf }}</ref> When deciding on a device, the cost of the device, a person's functional need, and the availability of a particular device should be considered.<ref name=":2" />

====Knee joint====
{{Main article|Knee replacement}}
In case of a trans-femoral (above knee) amputation, there also is a need for a complex connector providing articulation, allowing flexion during swing-phase but not during stance. As its purpose is to replace the knee, the prosthetic knee joint is the most critical component of the prosthesis for trans-femoral amputees. The function of the good prosthetic knee joint is to mimic the function of the normal knee, such as providing structural support and stability during stance phase but able to flex in a controllable manner during swing phase. Hence it allows users to have a smooth and energy efficient gait and minimize the impact of amputation.<ref>{{Cite journal|last1=Andrysek|first1=Jan|last2=Naumann|first2=Stephen|last3=Cleghorn|first3=William L.|date=December 2004|title=Design characteristics of pediatric prosthetic knees|journal=IEEE Transactions on Neural Systems and Rehabilitation Engineering |volume=12|issue=4|pages=369–378|doi=10.1109/TNSRE.2004.838444|issn=1534-4320|pmid=15614992|bibcode=2004ITNSR..12..369A |s2cid=1860735}}</ref> The prosthetic knee is connected to the prosthetic foot by the shank, which is usually made of an aluminum or graphite tube.

One of the most important aspect of a prosthetic knee joint would be its stance-phase control mechanism. The function of stance-phase control is to prevent the leg from buckling when the limb is loaded during weight acceptance. This ensures the stability of the knee in order to support the single limb support task of stance phase and provides a smooth transition to the swing phase. Stance phase control can be achieved in several ways including the mechanical locks,<ref>{{Cite thesis|title=Evaluation and Design of a Globally Applicable Rear-locking Prosthetic Knee Mechanism|url=https://tspace.library.utoronto.ca/handle/1807/33575|date=2012-11-27|degree=Thesis|language=en-ca|first=Dominik|last=Wyss}}</ref> relative alignment of prosthetic components,<ref name=":5">R. Stewart and A. Staros, "Selection and application of knee mechanisms," Bulletin of Prosthetics Research, vol. 18, pp. 90-158, 1972.</ref> weight activated friction control,<ref name=":5" /> and polycentric mechanisms.<ref>M. Greene, "Four bar linkage knee analysis," Prosthetics and Orthotics International, vol. 37, pp. 15-24, 1983.</ref>

=====Microprocessor control=====
To mimic the knee's functionality during gait, microprocessor-controlled knee joints have been developed that control the flexion of the knee. Some examples are [[Otto Bock]]'s C-leg, introduced in 1997, [[Ossur]]'s Rheo Knee, released in 2005, the Power Knee by Ossur, introduced in 2006, the Plié Knee from Freedom Innovations and DAW Industries' Self Learning Knee (SLK).<ref>[http://www.daw-usa.com/Pages/SLK3.html "The SLK, The Self-Learning Knee"] {{Webarchive|url=https://web.archive.org/web/20120425081600/http://www.daw-usa.com/Pages/SLK3.html |date=2012-04-25 }}, DAW Industries. Retrieved 16 March 2008.</ref>

The idea was originally developed by Kelly James, a Canadian engineer, at the [[University of Alberta]].<ref>{{Cite news|url= https://www.nytimes.com/2005/06/20/health/menshealth/20marrbox.html |title = Titanium and Sensors Replace Ahab's Peg Leg |access-date=2008-10-30 |work= The New York Times |date= 2005-06-20 | first=Michel | last=Marriott}}</ref>

A microprocessor is used to interpret and analyze signals from knee-angle sensors and moment sensors. The microprocessor receives signals from its sensors to determine the type of motion being employed by the amputee. Most microprocessor controlled knee-joints are powered by a battery housed inside the prosthesis.

The sensory signals computed by the microprocessor are used to control the resistance generated by [[hydraulic cylinders]] in the knee-joint. Small valves control the amount of [[hydraulic fluid]] that can pass into and out of the cylinder, thus regulating the extension and compression of a piston connected to the upper section of the knee.<ref name=PikeAlvin>Pike, Alvin (May/June 1999). "The New High Tech Prostheses". InMotion Magazine 9 (3)</ref>

The main advantage of a microprocessor-controlled prosthesis is a closer approximation to an amputee's natural gait. Some allow amputees to walk near walking speed or run. Variations in speed are also possible and are taken into account by sensors and communicated to the microprocessor, which adjusts to these changes accordingly. It also enables the amputees to walk downstairs with a step-over-step approach, rather than the one step at a time approach used with mechanical knees.<ref name=MartinCraigW>Martin, Craig W. (November 2003) [http://www.ibrarian.net/navon/paper/Evidence_Based_Practice_Group__EBPG_.pdf?paperid=2575568 "Otto Bock C-leg: A review of its effectiveness"] {{Webarchive|url=https://web.archive.org/web/20161228231356/http://www.ibrarian.net/navon/paper/Evidence_Based_Practice_Group__EBPG_.pdf?paperid=2575568 |date=2016-12-28 }}. WCB Evidence Based Group</ref> There is some research suggesting that people with microprocessor-controlled prostheses report greater satisfaction and improvement in functionality, residual limb health, and safety.<ref name="Kannenberg 2014 1469–1496">{{cite journal |last1=Kannenberg |first1=Andreas |last2=Zacharias |first2=Britta |last3=Pröbsting |first3=Eva |title=Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: Systematic review |journal=Journal of Rehabilitation Research and Development |date=2014 |volume=51 |issue=10 |pages=1469–1496 |doi=10.1682/JRRD.2014.05.0118 |pmid=25856664 |s2cid=5942534 }}</ref> People may be able to perform everyday activities at greater speeds, even while multitasking, and reduce their risk of falls.<ref name="Kannenberg 2014 1469–1496"/>

However, some have some significant drawbacks that impair its use. They can be susceptible to water damage and thus great care must be taken to ensure that the prosthesis remains dry.<ref>{{cite journal |last1=Highsmith |first1=M. Jason |last2=Kahle |first2=Jason T. |last3=Bongiorni |first3=Dennis R. |last4=Sutton |first4=Bryce S. |last5=Groer |first5=Shirley |last6=Kaufman |first6=Kenton R. |title=Safety, Energy Efficiency, and Cost Efficacy of the C-Leg for Transfemoral Amputees: A Review of the Literature |journal=Prosthetics and Orthotics International |date=December 2010 |volume=34 |issue=4 |pages=362–377 |doi=10.3109/03093646.2010.520054 |pmid=20969495 |s2cid=23608311 }}</ref>

===Myoelectric===
A '''myoelectric prosthesis''' uses the electrical tension generated every time a muscle contracts, as information. This tension can be captured from voluntarily contracted muscles by electrodes applied on the skin to control the movements of the prosthesis, such as elbow flexion/extension, wrist supination/pronation (rotation) or opening/closing of the fingers. A prosthesis of this type utilizes the residual neuromuscular system of the human body to control the functions of an electric powered prosthetic hand, wrist, elbow or foot.<ref>{{cite news|title=Amputees control bionic legs with their thoughts|url=https://www.reuters.com/article/us-iceland-mind-controlled-limb-idUSKBN0O51EQ20150520|work=Reuters|date=20 May 2015}}</ref> This is different from an electric switch prosthesis, which requires straps and/or cables actuated by body movements to actuate or operate switches that control the movements of the prosthesis. There is no clear evidence concluding that myoelectric upper extremity prostheses function better than body-powered prostheses.<ref name=Carey2015 /> Advantages to using a myoelectric upper extremity prosthesis include the potential for improvement in cosmetic appeal (this type of prosthesis may have a more natural look), may be better for light everyday activities, and may be beneficial for people experiencing [[phantom limb]] pain.<ref name=Carey2015>{{cite journal |last1=Carey |first1=Stephanie L. |last2=Lura |first2=Derek J. |last3=Highsmith |first3=M. Jason |last4=CP. |last5=FAAOP. |title=Differences in myoelectric and body-powered upper-limb prostheses: Systematic literature review |journal=Journal of Rehabilitation Research and Development |date=2015 |volume=52 |issue=3 |pages=247–262 |doi=10.1682/JRRD.2014.08.0192 |pmid=26230500 }}</ref> When compared to a body-powered prosthesis, a myoelectric prosthesis may not be as durable, may have a longer training time, may require more adjustments, may need more maintenance, and does not provide feedback to the user.<ref name=Carey2015 />

[[:es:Álvaro Ríos Poveda|Prof. Alvaro Ríos Poveda]] has been working for several years on a non-invasive and affordable solution to this feedback problem. He considers that: "Prosthetic limbs that can be controlled with thought hold great promise for the amputee, but without sensorial feedback from the signals returning to the brain, it can be difficult to achieve the level of control necessary to perform precise movements. When connecting the sense of touch from a mechanical hand directly to the brain, prosthetics can restore the function of the amputated limb in an almost natural-feeling way." He presented the first Myoelectric prosthetic hand with sensory feedback at the ''XVIII World Congress on Medical Physics and Biomedical Engineering'', 1997, held in [[Nice, France]].<ref>{{cite web |author1=((International Federation for Medical and Biological Engineering)) |author1-link=International Federation for Medical and Biological Engineering |title=World Congress on Medical Physics and Biomedical Engineering |url=https://ifmbe.org/events/world-congress/ |website=IFMBE |access-date=19 March 2022 |date=17 December 2012}}</ref><ref>{{cite conference |last1=Rios |first1=Alvaro |title=Microcontroller system for myoelectric prosthesis with sensory feedback |conference=World Congress on Medical Physics and Biomedical Engineering: XVIII International Conference on Medical and Biological Engineering and XI International Conference on Medical Physics |year =1997 |location=Nice, France}}</ref>

The USSR was the first to develop a myoelectric arm in 1958,<ref>{{cite journal|pmid=365281|year=1978|last1=Wirta|first1=R. W.|title=Pattern-recognition arm prosthesis: A historical perspective-a final report|journal=Bulletin of Prosthetics Research|pages=8–35|last2=Taylor|first2=D. R.|last3=Finley|first3=F. R.|url=http://www.rehab.research.va.gov/jour/78/15/2/wirta.pdf}}</ref> while the first myoelectric arm became commercial in 1964 by the Central Prosthetic Research Institute of the [[Soviet Union|USSR]], and distributed by the Hangar Limb Factory of the [[United Kingdom|UK]].<ref>{{Cite journal
  | last = Sherman
  | first = E. David
  | title = A Russian Bioelectric-Controlled Prosthesis: Report of a Research Team from the Rehabilitation Institute of Montreal
  | journal = Canadian Medical Association Journal
  | volume = 91
  | issue = 24
  | pages = 1268–1270
  | year = 1964
| pmc=1927453
| pmid=14226106}}</ref><ref>{{Cite book
  | last = Muzumdar
  | first = Ashok
  | title = Powered Upper Limb Prostheses: Control, Implementation and Clinical Application
  | publisher = Springer
  | year = 2004
  | isbn = 978-3-540-40406-4}}</ref> Myoelectric prosthesis are expensive, require regular maintenance, and are sensitive to sweat and moisture.

===Robotic prostheses===
[[File:An-Electrocorticographic-Brain-Interface-in-an-Individual-with-Tetraplegia-pone.0055344.s009.ogv|thumb|Brain control of 3D prosthetic arm movement (hitting targets). This movie was recorded when the participant controlled the 3D movement of a prosthetic arm to hit physical targets in a research lab.]]
{{Main|Neural prosthetics|Powered exoskeleton#Current products (powered exoskeletons)}}
{{Further|Robotics#Touch|3-D printing|Open-source hardware}}

Robots can be used to generate objective measures of patient's impairment and therapy outcome, assist in diagnosis, customize therapies based on patient's motor abilities, and assure compliance with treatment regimens and maintain patient's records. It is shown in many studies that there is a significant improvement in upper limb motor function after stroke using robotics for upper limb rehabilitation.<ref>{{cite journal | author = Reinkensmeyer David J | year = 2009 | title = Robotic Assistance For Upper Extremity Training After Stroke | journal = Studies in Health Technology and Informatics | volume = 145 | pages = 25–39 | pmid = 19592784 | url = http://computational.eu/emerging//book9/chapter_2.pdf | access-date = 2016-12-28 | archive-url = https://web.archive.org/web/20161228195545/http://computational.eu/emerging//book9/chapter_2.pdf | archive-date = 2016-12-28 }}</ref>
In order for a robotic prosthetic limb to work, it must have several components to integrate it into the body's function: [[Biosensors]] detect signals from the user's nervous or muscular systems. It then relays this information to a [[microcontroller]] located inside the device, and processes feedback from the limb and actuator, e.g., position or force, and sends it to the controller. Examples include surface electrodes that detect electrical activity on the skin, needle electrodes implanted in muscle, or solid-state electrode arrays with nerves growing through them. One type of these biosensors are employed in [[myoelectric prosthesis|myoelectric prostheses]].

A device known as the controller is connected to the user's nerve and muscular systems and the device itself. It sends intention commands from the user to the actuators of the device and interprets feedback from the mechanical and biosensors to the user. The controller is also responsible for the monitoring and control of the movements of the device.

An [[actuator]] mimics the actions of a muscle in producing force and movement. Examples include a motor that aids or replaces original muscle tissue.

Targeted muscle reinnervation (TMR) is a technique in which [[motor nerve]]s, which previously controlled [[muscle]]s on an amputated limb, are [[surgery|surgically]] rerouted such that they reinnervate a small region of a large, intact muscle, such as the [[pectoralis major]]. As a result, when a patient thinks about moving the thumb of their missing hand, a small area of muscle on their chest will contract instead. By placing sensors over the reinnervated muscle, these contractions can be made to control the movement of an appropriate part of the robotic prosthesis.<ref name="six">{{Cite journal|vauthors=Kuiken TA, Miller LA, Lipschutz RD, Lock BA, Stubblefield K, Marasco PD, Zhou P, Dumanian GA |title=Targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation: a case study |journal=Lancet |date= February 3, 2007 |volume=369 |issue=9559 |pages=371–80 |pmid=17276777 |doi=10.1016/S0140-6736(07)60193-7|s2cid=20041254 }}</ref><ref>{{cite web|url=http://www.technologyreview.com/blog/editors/22730/ |title=Blogs: TR Editors' blog: Patients Test an Advanced Prosthetic Arm |work=Technology Review |date=2009-02-10 |access-date=2010-10-03}}</ref>

A variant of this technique is called targeted sensory reinnervation (TSR). This procedure is similar to TMR, except that [[sensory nerve]]s are surgically rerouted to [[skin]] on the chest, rather than motor nerves rerouted to muscle. Recently, robotic limbs have improved in their ability to take signals from [[Human brain|the human brain]] and translate those signals into motion in the artificial limb. [[DARPA]], the Pentagon's research division, is working to make even more advancements in this area. Their desire is to create an artificial limb that ties directly into the [[nervous system]].<ref name="seven">{{cite web |url=http://www.darpa.mil/dso/solicitations/sn07-43.htm |title=Defense Sciences Office |publisher=Darpa.mil |access-date=2010-10-03 |archive-url=https://web.archive.org/web/20090426080528/http://www.darpa.mil/dso/solicitations/sn07-43.htm |archive-date=2009-04-26 }}</ref>

====Robotic arms====
Advancements in the processors used in myoelectric arms have allowed developers to make gains in fine-tuned control of the prosthetic. The [[Boston Digital Arm]] is a recent artificial limb that has taken advantage of these more advanced processors. The arm allows movement in five axes and allows the arm to be programmed for a more customized feel. Recently the [[I-LIMB Hand]], invented in Edinburgh, Scotland, by [[David Gow]] has become the first commercially available hand prosthesis with five individually powered digits. The hand also possesses a manually rotatable thumb which is operated passively by the user and allows the hand to grip in precision, power, and key grip modes.<ref>{{Cite journal|last1=Binedell|first1=Trevor|last2=Meng|first2=Eugene|last3=Subburaj|first3=Karupppasamy|date=2020-08-25|title=Design and development of a novel 3D-printed non-metallic self-locking prosthetic arm for a forequarter amputation|journal=Prosthetics and Orthotics International|volume=45|pages=94–99|doi=10.1177/0309364620948290|issn=1746-1553|pmid=32842869|s2cid=221326246}}</ref>

Another neural prosthetic is [[Johns Hopkins University Applied Physics Laboratory]] Proto 1. Besides the Proto 1, the university also finished the [[Proto 2]] in 2010.<ref>{{cite web |url=http://www.ric.org/aboutus/mediacenter/press/2007/o501.aspx |title=Proto 1 and Proto 2 |publisher=Ric.org |date=2007-05-01 |access-date=2010-10-03 |archive-url=https://web.archive.org/web/20110727215917/http://www.ric.org/aboutus/mediacenter/press/2007/o501.aspx |archive-date=2011-07-27 }}</ref> Early in 2013, Max Ortiz Catalan and Rickard Brånemark of the Chalmers University of Technology, and Sahlgrenska University Hospital in Sweden, succeeded in making the first robotic arm which is mind-controlled and can be permanently attached to the body (using [[osseointegration]]).<ref>{{cite web|url=https://www.sciencedaily.com/releases/2013/02/130222075730.htm |title=World premiere of muscle and nerve controlled arm prosthesis |publisher=Sciencedaily.com |date=February 2013 |access-date=2016-12-28}}</ref><ref>{{cite web|url=http://www.gizmag.com/thought-controlled-prosthetic-arm/25216/ |title=Mind-controlled permanently-attached prosthetic arm could revolutionize prosthetics |publisher=Gizmag.com |date=2012-11-30 |access-date=2016-12-28 |author=Williams, Adam }}</ref><ref>{{cite web|last=Ford |first=Jason |url=http://www.theengineer.co.uk/sectors/medical-and-healthcare/news/trials-imminent-for-implantable-thought-controlled-robotic-arm/1014779.article |title=Trials imminent for implantable thought-controlled robotic arm |publisher=Theengineer.co.uk |date=2012-11-28 |access-date=2016-12-28}}</ref>

An approach that is very useful is called arm rotation which is common for unilateral amputees which is an amputation that affects only one side of the body; and also essential for bilateral amputees, a person who is missing or has had amputated either both arms or legs, to carry out activities of daily living. This involves inserting a small permanent magnet into the distal end of the residual bone of subjects with upper limb amputations. When a subject rotates the residual arm, the magnet will rotate with the residual bone, causing a change in magnetic field distribution.<ref>{{cite journal |author1=Li, Guanglin |author2=Kuiken, Todd A | year = 2008 | title = Modeling of Prosthetic Limb Rotation Control by Sensing Rotation of Residual Arm Bone | journal = IEEE Transactions on Biomedical Engineering | volume = 55 | issue = 9| pages = 2134–2142 | doi=10.1109/tbme.2008.923914| pmc=3038244 | pmid=18713682 |bibcode=2008ITBE...55.2134L }}</ref> EEG (electroencephalogram) signals, detected using small flat metal discs attached to the scalp, essentially decoding human brain activity used for physical movement, is used to control the robotic limbs. This allows the user to control the part directly.<ref>{{cite journal | author = Contreras-Vidal José L. | year = 2012 | title = Restoration of Whole Body Movement: Toward a Noninvasive Brain-Machine Interface System | journal = IEEE Pulse | volume = 3 | issue = 1| pages = 34–37 | doi=10.1109/mpul.2011.2175635| pmid = 22344949 |display-authors=etal| pmc = 3357625}}</ref>

====Robotic transtibial prostheses ====
The research of robotic legs has made some advancement over time, allowing exact movement and control.

Researchers at the [[Rehabilitation Institute of Chicago]] announced in September 2013 that they have developed a robotic leg that translates neural impulses from the user's thigh muscles into movement, which is the first prosthetic leg to do so. It is currently in testing.<ref>{{cite web|url=http://www.medgadget.com/2013/09/robotic-leg-emg.html |title=Rehabilitation Institute of Chicago First to Develop Thought Controlled Robotic Leg |work=Medgadget |publisher=Medgadget.com |date=September 2013 |access-date=2016-12-28}}</ref>

Hugh Herr, head of the biomechatronics group at MIT's Media Lab developed a robotic transtibial leg (PowerFoot BiOM).<ref>{{cite web |last1=Shaer |first1=Matthew |title=Is This the Future of Robotic Legs? |url=https://www.smithsonianmag.com/innovation/future-robotic-legs-180953040/ |website=Smithsonian Magazine |language=en|date=November 2014}}</ref><ref>{{cite web|url = https://biomech.media.mit.edu/portfolio_page/powered-ankle-foot-prosthesis/ |title = Transtibial Powered Prostheses|website = Biomechatronics|publisher = MIT Media Lab}}</ref>

The Icelandic company Össur has also created a robotic transtibial leg with motorized ankle that moves through algorithms and sensors that automatically adjust the angle of the foot during different points in its wearer's stride. Also there are brain-controlled bionic legs that allow an individual to move his limbs with a wireless transmitter.<ref>{{Cite news|url=https://www.popsci.com/brain-controlled-bionic-legs-are-here-no-really|title=Brain-Controlled Bionic Legs Are Finally Here|work=Popular Science|access-date=2018-12-01|language=en|first1=Erik|last1=Sofge|date=20 May 2015}}</ref>

====Prosthesis design====
The main goal of a robotic prosthesis is to provide active actuation during gait to improve the biomechanics of gait, including, among other things, stability, symmetry, or energy expenditure for amputees.<ref>{{Cite journal|last1=Liacouras|first1=Peter C.|last2=Sahajwalla|first2=Divya|last3=Beachler|first3=Mark D.|last4=Sleeman|first4=Todd|last5=Ho|first5=Vincent B.|last6=Lichtenberger|first6=John P.|date=2017|title=Using computed tomography and 3D printing to construct custom prosthetics attachments and devices|journal=3D Printing in Medicine|volume=3|issue=1|page=8|doi=10.1186/s41205-017-0016-1|issn=2365-6271|pmc=5954798|pmid=29782612 |doi-access=free }}</ref> There are several powered prosthetic legs currently on the market, including fully powered legs, in which actuators directly drive the joints, and semi-active legs, which use small amounts of energy and a small actuator to change the mechanical properties of the leg but do not inject net positive energy into gait. Specific examples include The emPOWER from BionX, the Proprio Foot from Ossur, and the Elan Foot from Endolite.<ref>{{Cite web|url=http://www.bionxmed.com/|title=Home – BionX Medical Technologies|website=www.bionxmed.com|language=en-US|access-date=2018-01-08|archive-date=2017-12-03|archive-url=https://web.archive.org/web/20171203114709/http://www.bionxmed.com/}}</ref><ref>{{Cite web|url=https://www.ossur.com/prosthetic-solutions/products/dynamic-solutions/proprio-foot|title=PROPRIO FOOT|last=Össur|website=www.ossur.com|language=en-us|access-date=2018-01-08}}</ref><ref>{{Cite news|url=http://www.endolite.com/products/elan|title=Elan – Carbon, Feet, Hydraulic – Endolite USA – Lower Limb Prosthetics|work=Endolite USA – Lower Limb Prosthetics|access-date=2018-01-08|language=en-US}}</ref> Various research groups have also experimented with robotic legs over the last decade.<ref>{{cite journal |last1=Windrich |first1=Michael |last2=Grimmer |first2=Martin |last3=Christ |first3=Oliver |last4=Rinderknecht |first4=Stephan |last5=Beckerle |first5=Philipp |title=Active lower limb prosthetics: a systematic review of design issues and solutions |journal=BioMedical Engineering OnLine |date=19 December 2016 |volume=15 |issue=S3 |page=140 |doi=10.1186/s12938-016-0284-9 |pmid=28105948 |pmc=5249019 |doi-access=free }}</ref> Central issues being researched include designing the behavior of the device during stance and swing phases, recognizing the current ambulation task, and various mechanical design problems such as robustness, weight, battery-life/efficiency, and noise-level. However, scientists from [[Stanford University]] and [[Seoul National University of Science and Technology|Seoul National University]] has developed artificial nerves system that will help prosthetic limbs feel.<ref>{{Cite web|url=https://www.engineering.com/DesignerEdge/DesignerEdgeArticles/ArticleID/17049/Researchers-Create-Artificial-Nerve-System.aspx|title=Researchers Create Artificial Nerve System|last=ENGINEERING.com|website=www.engineering.com|language=en-US|access-date=2018-06-08}}</ref> This synthetic nerve system enables prosthetic limbs sense [[braille]], feel the sense of touch and respond to the environment.<ref>{{Cite web|url=http://www.xinhuanet.com/english/2018-06/01/c_137223459.htm|archive-url=https://web.archive.org/web/20180607021506/http://www.xinhuanet.com/english/2018-06/01/c_137223459.htm|archive-date=June 7, 2018|title=Stanford researchers create artificial nerve system for robots – Xinhua {{!}} English.news.cn|website=www.xinhuanet.com|access-date=2018-06-08}}</ref><ref>{{Cite news|url=https://news.stanford.edu/2018/05/31/artificial-nerve-system-gives-prosthetic-devices-robots-sense-touch/|title=An artificial nerve system gives prosthetic devices and robots a sense of touch {{!}} Stanford News|last=University|first=Stanford|date=2018-05-31|work=Stanford News|access-date=2018-06-08|language=en-US}}</ref>

===Use of recycled materials===
Prosthetics are being made from recycled plastic bottles and lids around the world.<ref>{{cite web | title=Affordable prosthetics made from recycled plastic waste | website=MaterialDistrict | date=14 January 2019 | url=https://materialdistrict.com/article/prosthetics-recycled-plastic/ | access-date=3 November 2020}}</ref><ref name="World Economic Forum 2019">{{cite web | title=These researchers are turning plastic bottles into prosthetic limbs | website=World Economic Forum | date=4 October 2019 | url=https://www.weforum.org/agenda/2019/10/plastic-bottles-waste-prosthetic-limbs/ | access-date=3 November 2020}}</ref><ref>{{cite web | last=Bell | first=Sarah Jane | title=Recycling shampoo bottles to make prosthetic limbs becomes retired hairdresser's dream| website=ABC News|publisher=Australian Broadcasting Corporation | date=21 April 2019 | url=https://www.abc.net.au/news/2019-04-22/recycled-plastic-made-into-prosthetic-limbs/10992038 | access-date=3 November 2020}}</ref><ref name="Conway 2019">{{cite web | last=Conway | first=Elle | title=Canberra family turning bottle caps into plastic hands and arms for children  | website=ABC News|publisher=Australian Broadcasting Corporation | date=26 June 2019 | url=https://www.abc.net.au/news/2019-06-27/lids-for-kids-canberra-collection-volunteer-envision-hands/11249628 | access-date=3 November 2020}}</ref><ref>{{cite web | title=Envision Hands | website=Envision | date=19 February 2020 | url=https://envision.org.au/envision-hands/ | access-date=3 November 2020}}</ref>

== {{anchor|endoprosthesis|endo-exoprothesis|prosthetic implant|prosthetic joint implant}} Direct bone attachment and osseointegration ==
{{Main|Osseointegration}}

Most prostheses are attached to the exterior of the body in a non-permanent way. The stump and socket method can cause significant pain for the person, which is why direct bone attachment has been explored extensively. 

[[Osseointegration]] is a method of attaching the artificial limb to the body by a prosthetic implant. 
This method is also sometimes referred to as ''[[exoprosthesis]]'' (attaching an artificial limb to the bone), or ''endo-exoprosthesis''.
''Endoprosthesis'' are prosthetic joint implants which remain wholly inside the body such as [[knee replacement|knee]] and [[hip replacement]] implants.

The method works by inserting a titanium bolt into the bone at the end of the stump. After several months the [[osseointegration|bone attaches itself]] to the titanium bolt and an abutment is attached to the titanium bolt. The abutment extends out of the stump and the (removable) artificial limb is then attached to the abutment. Some of the benefits of this method include the following:
* Better muscle control of the prosthetic.
* The ability to wear the prosthetic for an extended period of time; with the stump and socket method this is not possible.
* The ability for transfemoral amputees to drive a car.
The main disadvantage of this method is that amputees with the direct bone attachment cannot have large impacts on the limb, such as those experienced during jogging, because of the potential for the bone to break.<ref name="four"/>

==Cosmesis==
Cosmetic prosthesis has long been used to disguise injuries and disfigurements. With advances in modern technology, [[cosmesis]], the creation of lifelike limbs made from [[silicone]] or [[PVC]], has been made possible.<ref>{{Cite journal|last1=Thomas|first1=Daniel J.|last2=Singh|first2=Deepti|date=August 2020|title=3D printing for developing patient specific cosmetic prosthetics at the point of care|journal=International Journal of Surgery|volume=80|pages=241–242|doi=10.1016/j.ijsu.2020.04.023|issn=1743-9159|pmid=32311524|s2cid=216047962}}</ref> Such prosthetics, including artificial hands, can now be designed to simulate the appearance of real hands, complete with freckles, veins, hair, fingerprints and even tattoos.
Custom-made cosmeses are generally more expensive (costing thousands of U.S. dollars, depending on the level of detail), while standard cosmeses come premade in a variety of sizes, although they are often not as realistic as their custom-made counterparts. Another option is the custom-made silicone cover, which can be made to match a person's skin tone but not details such as freckles or wrinkles. Cosmeses are attached to the body in any number of ways, using an adhesive, suction, form-fitting, stretchable skin, or a skin sleeve.

==Cognition==
{{Main|Neuroprosthetics}}

Unlike neuromotor prostheses, neurocognitive prostheses would sense or modulate neural function in order to physically reconstitute or augment cognitive processes such as [[executive function]], [[attention]], language, and memory. No neurocognitive prostheses are currently available but the development of implantable neurocognitive brain-computer interfaces has been proposed to help treat conditions such as [[stroke]], [[traumatic brain injury]], [[cerebral palsy]], [[autism]], and [[Alzheimer's disease]].<ref name="Serruya MD, Kahana MJ 2008 149">{{Cite journal|journal= Behav Brain Res |year=2008 |title= Techniques and devices to restore cognition |vauthors=Serruya MD, Kahana MJ |doi=10.1016/j.bbr.2008.04.007 |pmid=18539345 |volume= 192 |issue= 2|pages= 149–65|pmc= 3051349}}</ref>
The recent field of Assistive Technology for Cognition concerns the development of technologies to augment human cognition. Scheduling devices such as Neuropage remind users with memory impairments when to perform certain activities, such as visiting the doctor. Micro-prompting devices such as PEAT, AbleLink and Guide have been used to aid users with memory and executive function problems perform [[activities of daily living]].

==Prosthetic enhancement==
{{Further|Powered exoskeleton#Research}}
[[File:Flickr - The U.S. Army - U.S. Army World Class Athlete Program Paralympic.jpg|thumb|right|upright|Sgt. Jerrod Fields works out at the U.S. Olympic Training Center in Chula Vista, California.]]
In addition to the standard artificial limb for everyday use, many amputees or [[congenital]] patients have special limbs and devices to aid in the participation of sports and recreational activities.

Within science fiction, and, more recently, within the [[scientific community]], there has been consideration given to using advanced prostheses to replace healthy body parts with artificial mechanisms and systems to improve function. The morality and desirability of such technologies are being debated by [[transhumanists]], other ethicists, and others in general.<ref>{{cite web |url=http://www.practicalethics.ox.ac.uk/ht/enhancement/main |title=Enhancements, Oxford Uehiro Centre for Practical Ethics |publisher=Practicalethics.ox.ac.uk |access-date=2016-12-28 |archive-url=https://web.archive.org/web/20161228205218/http://www.practicalethics.ox.ac.uk/ht/enhancement/main |archive-date=2016-12-28 }}</ref><ref>{{cite journal|doi=10.1371/journal.pmed.0010052 |pmid=15630464 |title=Is It Ethical to Use Enhancement Technologies to Make Us Better than Well? |journal=PLOS Medicine |volume=1 |issue=3 |article-number=e52 |year=2004 |last1=Caplan |first1=Arthur |last2=Elliott |first2=Carl |pmc=539045 |doi-access=free }}</ref><ref>{{cite book|doi=10.1093/acprof:oso/9780199587810.001.0001 |title=Beyond Humanity? |year=2011 |last1=Buchanan |first1=Allen E. |isbn=978-0-19-958781-0}}</ref><ref>{{cite journal|doi=10.1111/j.1467-8519.2012.01964.x|title=Beyond Humanity? The Ethics of Biomedical Enhancement – by Allen Buchanan|journal=Bioethics|volume=26|issue=7|pages=391–392|year=2012|last1=Anomaly|first1=Jonny}}</ref> Body parts such as legs, arms, hands, feet, and others can be replaced.

The first experiment with a healthy individual appears to have been that by the British scientist [[Kevin Warwick]]. In 2002, an [[implant (medicine)|implant]] was interfaced directly into Warwick's nervous system. The [[electrode array]], which contained around a hundred [[electrode]]s, was placed in the [[median nerve]]. The signals produced were detailed enough that a [[robot arm]] was able to mimic the actions of Warwick's own arm and provide a form of touch feedback again via the implant.<ref name="Warwick, K 1373">{{cite journal |vauthors=Warwick K, Gasson M, Hutt B, Goodhew I, Kyberd P, Andrews B, Teddy P, Shad A | year = 2003 | title = The Application of Implant Technology for Cybernetic Systems | journal = Archives of Neurology | volume = 60 | issue = 10| pages = 1369–1373 | doi=10.1001/archneur.60.10.1369 | pmid=14568806}}</ref>

The [[DEKA (company)|DEKA]] company of [[Dean Kamen]] developed the "Luke arm", an advanced [[Neuroprosthetics#Motor prosthetics for conscious control of movement|nerve-controlled prosthetic]]. Clinical trials began in 2008,<ref name="spectrum.ieee.org">{{cite web|url=https://spectrum.ieee.org/dean-kamens-luke-arm-prosthesis-readies-for-clinical-trials |author=Adee, Sarah |date=2008-02-01|title=Dean Kamen's "Luke Arm" Prosthesis Readies for Clinical Trials |work=IEEE Spectrum }}</ref> with FDA approval in 2014 and commercial manufacturing by the [[Universal Instruments Corporation]] expected in 2017. The price offered at retail by Mobius Bionics is expected to be around $100,000.<ref>{{Cite web | url=https://www.meddeviceonline.com/doc/darpa-s-mind-controlled-arm-prosthesis-preps-for-commercial-launch-0001 | title=DARPA's Mind-Controlled Arm Prosthesis Preps for Commercial Launch}}</ref>

Further research in April 2019, there have been improvements towards prosthetic function and comfort of 3D-printed personalized wearable systems. Instead of manual integration after printing, integrating electronic sensors at the intersection between a prosthetic and the wearer's tissue can gather information such as pressure across wearer's tissue, that can help improve further iteration of these types of prosthetic.<ref>{{Cite web|url=https://www.scitecheuropa.eu/3d-printed-prosthetics/94078/|title=Wearable system interfaces: How can electronic sensors be integrated into improved 3D printed prosthetics?|last=Garner|first=Courtney|date=2019-04-05|website=SciTech Europa|language=en-GB|access-date=2019-05-06}}</ref>

===Oscar Pistorius===
In early 2008, [[Oscar Pistorius]], the "Blade Runner" of South Africa, was briefly ruled ineligible to compete in the [[2008 Summer Olympics]] because his transtibial prosthesis limbs were said to give him an unfair advantage over runners who had ankles. One researcher found that his limbs used twenty-five percent less energy than those of a non-disabled runner moving at the same speed. This ruling was overturned on appeal, with the appellate court stating that the overall set of advantages and disadvantages of Pistorius' limbs had not been considered.

Pistorius did not qualify for the South African team for the Olympics, but went on to sweep the [[2008 Summer Paralympics]], and has been ruled eligible to qualify for any future Olympics.{{citation needed|date=May 2017}} He qualified for the 2011 World Championship in South Korea and reached the semi-final where he ended last timewise, he was 14th in the first round, his personal best at 400m would have given him 5th place in the finals. At the [[2012 Summer Olympics]] in London, Pistorius became the first amputee runner to compete at an Olympic Games.<ref>{{citation|author=Robert Klemko|title=Oscar Pistorius makes history, leaves without medal|url=https://www.usatoday.com/sports/olympics/london/track/story/2012-08-10/4x400-relay-oscar-pistorius-south-afric/56946372/1|archive-url=https://web.archive.org/web/20120811151754/http://www.usatoday.com/sports/olympics/london/track/story/2012-08-10/4x400-relay-oscar-pistorius-south-afric/56946372/1|archive-date=11 August 2012|newspaper=USA Today|date=10 August 2012}}</ref> He ran in the [[athletics at the 2012 Summer Olympics&nbsp;– Men's 400 metres|400&nbsp;metres race]] semi-finals,<ref name="BBC 20120804">{{citation|title=Oscar Pistorius makes Olympic history in 400m at London 2012|url=https://www.bbc.co.uk/sport/olympics/18911479|publisher=BBC Sport|date=4 August 2012}}</ref><ref>{{citation|author=Bill Chappell|title=Oscar Pistorius makes Olympic history in 400 meters, and moves on to semi-final|url=https://www.npr.org/blogs/thetorch/2012/08/04/158126486/oscar-pistorius-makes-olympic-history-in-400-meters-and-moves-on-to-semifinal|archive-url=https://web.archive.org/web/20120804164207/http://www.npr.org/blogs/thetorch/2012/08/04/158126486/oscar-pistorius-makes-olympic-history-in-400-meters-and-moves-on-to-semifinal|archive-date=4 August 2012|publisher=[[NPR]]|date=4 August 2012}}</ref><ref>{{citation|title=Men's 400m&nbsp;– semi-finals|url=http://www.london2012.com/athletics/event/men-400m/phase=atm004200/index.html|access-date=4 August 2012|work=london2012.com|archive-url=https://archive.today/20121216094759/http://www.london2012.com/athletics/event/men-400m/phase=atm004200/index.html|archive-date=16 December 2012|df=dmy-all}}</ref> and the [[athletics at the 2012 Summer Olympics&nbsp;– Men's 4 × 400 metres relay|4&nbsp;×&nbsp;400&nbsp;metres relay race]] finals.<ref>{{citation|title=Oscar Pistorius, South African 4×400m relay team finish 8th as Bahamas wins gold|url=http://www.huffingtonpost.com/2012/08/10/oscar-pistorius-south-africa-relay-4x400-olympics_n_1765596.html|archive-url=https://web.archive.org/web/20120810224029/http://www.huffingtonpost.com/2012/08/10/oscar-pistorius-south-africa-relay-4x400-olympics_n_1765596.html|archive-date=10 August 2012|newspaper=Huffington Post|date=10 August 2012|first=Chris|last=Greenberg}}</ref> He also competed in 5 events in the [[2012 Summer Paralympics]] in London.<ref>{{cite news|title=Hawking, Pistorius open London's Paralympics: Wheelchair-bound physicist Stephen Hawking challenged athletes to 'look to the stars' as he helped open a record-setting Paralympics Games that will run for 11 days in near sold-out venues|url=http://uk.eurosport.yahoo.com/news/hawking-pistorius-open-londons-paralympics-194425194.html|agency= Reuters |date=29 August 2012 |archive-url=https://web.archive.org/web/20120902025159/http://uk.eurosport.yahoo.com/news/hawking-pistorius-open-londons-paralympics-194425194.html|archive-date=2 September 2012|work=[[Yahoo! Sports]]}}</ref>

==Design considerations==
There are multiple factors to consider when designing a transtibial prosthesis. Manufacturers must make choices about their priorities regarding these factors.

===Performance===
Nonetheless, there are certain elements of socket and foot mechanics that are invaluable for the athlete, and these are the focus of today's high-tech prosthetics companies:
* Fit&nbsp;– athletic/active amputees, or those with bony residua, may require a carefully detailed socket fit; less-active patients may be comfortable with a 'total contact' fit and gel liner
* Energy storage and return&nbsp;– storage of energy acquired through ground contact and utilization of that stored energy for propulsion
* Energy absorption&nbsp;– minimizing the effect of high impact on the musculoskeletal system
* Ground compliance&nbsp;– stability independent of terrain type and angle
* Rotation&nbsp;– ease of changing direction
* Weight&nbsp;– maximizing comfort, balance and speed
* Suspension&nbsp;– how the socket will join and fit to the limb

===Other===
The buyer is also concerned with numerous other factors:
* Cosmetics
* Cost
* Ease of use
* Size availability

=== Design for Prosthetics ===
A key feature of prosthetics and prosthetic design is the idea of "designing for disabilities." This might sound like a good idea in which people with disabilities can participate in equitable design but this is unfortunately not true. The idea of designing for disabilities is first problematic because of the underlying meaning of disabilities. It tells amputees that there is a right and wrong way to move and walk and that if amputees are adapted to the surrounding environment by their own means, then that is the wrong way. Along with that underlying meaning of disabilities, many people designing for disabilities are not actually disabled. "Design for disability" from these experiences, takes disability as the object - with the feeling from non-disabled designers that they have properly learned about their job from their own simulation of the experience. The simulation is misleading and does a disservice to disabled people - so the design that flows from this is highly problematic. Engaging in disability design should be… with, ideally, team members who have the relevant disability and are part of communities that matter to the research.<ref>{{Cite journal |last=Shew |first=Ashley |date=2022-03-16 |title=How To Get A Story Wrong: Technoableism, Simulation, and Cyborg Resistance |url=https://ojs.scholarsportal.info/ontariotechu/index.php/id/article/view/169 |journal=Including Disability |volume=1 |language=en |issue=1 |pages=13–36 |doi=10.51357/id.vi1.169 |issn=2817-6731|hdl=10919/113653 |hdl-access=free }}</ref> This leads to people, who do not know what the day-to-day personal experiences are, designing materials that do not meet the needs or hinder the needs of people with actual disabilities.

==Cost and source freedom==

===High-cost===
In the United States, a typical prosthetic limb costs anywhere between $15,000 and $90,000, depending on the type of limb desired by the patient. With medical insurance, a patient will typically pay 10%–50% of the total cost of a prosthetic limb, while the insurance company will cover the rest of the cost. The percent that the patient pays varies on the type of insurance plan, as well as the limb requested by the patient.<ref name="Cost of a Prosthetic Limb">{{cite web|title=Cost of a Prosthetic Limb|url=http://health.costhelper.com/prosthetic-legs.html|website=Cost Helper Health|access-date= 13 April 2015}}</ref> In the United Kingdom, much of Europe, Australia and New Zealand the entire cost of prosthetic limbs is met by state funding or statutory insurance. For example, in Australia prostheses are fully funded by state schemes in the case of amputation due to disease, and by workers compensation or traffic injury insurance in the case of most traumatic amputations.<ref>{{cite web|title=Funding for your prosthesis.|url=http://www.limbs4life.org.au/funding/funding-for-your-prosthesis|website=Limbs4life|access-date=28 January 2018}}</ref> The [[National Disability Insurance Scheme]], which is being rolled out nationally between 2017 and 2020 also pays for prostheses.

Transradial (below the elbow amputation) and transtibial prostheses (below the knee amputation) typically cost between US [[United States dollar|$]]6,000 and $8,000, while transfemoral (above the knee amputation) and transhumeral prosthetics (above the elbow amputation) cost approximately twice as much with a range of $10,000 to $15,000 and can sometimes reach costs of $35,000. The cost of an artificial limb often recurs, while a limb typically needs to be replaced every 3–4 years due to [[wear and tear]] of everyday use. In addition, if the socket has fit issues, the socket must be replaced within several months from the onset of pain. If height is an issue, components such as pylons can be changed.<ref name="eight">[http://www.boston.com/business/globe/articles/2005/07/05/cost_of_prosthetics_stirs_debate/ "Cost of Prosthetics Stirs Debate"], ''[[Boston Globe]]'', 5 July 2005. Retrieved 11 February 2007.</ref>

Not only does the patient need to pay for their multiple prosthetic limbs, but they also need to pay for physical and occupational therapy that come along with adapting to living with an artificial limb. Unlike the reoccurring cost of the prosthetic limbs, the patient will typically only pay the $2000 to $5000 for therapy during the first year or two of living as an amputee. Once the patient is strong and comfortable with their new limb, they will not be required to go to therapy anymore. Throughout one's life, it is projected that a typical amputee will go through $1.4&nbsp;million worth of treatment, including surgeries, prosthetics, as well as therapies.<ref name="Cost of a Prosthetic Limb"/>

===Low-cost===
{{See also|3D Printed Prosthesis|3D printing}}

Low-cost above-knee prostheses often provide only basic structural support with limited function. This function is often achieved with crude, non-articulating, unstable, or manually locking knee joints. A limited number of organizations, such as the International Committee of the Red Cross (ICRC), create devices for developing countries. Their device which is manufactured by CR Equipments is a single-axis, manually operated locking polymer prosthetic knee joint.<ref>{{cite web|url=http://www.icrc.org/Web/eng/siteeng0.nsf/htmlall/p0868/$File/Eng-Transfemoral.pdf |title=ICRC: Trans-Femoral Prosthesis&nbsp;– Manufacturing Guidelines |access-date=2010-10-03}}</ref>

Table. List of knee joint technologies based on the literature review.<ref name="ReferenceB"/>
{| class="wikitable"
|-
! Name of technology (country of origin) !!  Brief description !! Highest level of
evidence
|-
| ICRC knee (Switzerland) || Single-axis with manual lock || Independent field
|-
| ATLAS knee (UK) || Weight-activated friction || Independent field
|-
| POF/OTRC knee (US) || Single-axis with ext. assist || Field
|-
| DAV/Seattle knee (US) || Compliant polycentric || Field
|-
| LIMBS International M1 knee (US) || Four-bar || Field
|-
| JaipurKnee (India) || Four-bar || Field
|-
| LCKnee (Canada) || Single-axis with automatic lock || Field
|-
| None provided (Nepal) || Single-axis || Field
|-
| None provided (New Zealand) || Roto-molded single-axis || Field
|-
| None provided (India) || Six-bar with squatting || Technical development
|-
| Friction knee (US) || Weight-activated friction || Technical development
|-
| Wedgelock knee (Australia) || Weight-activated friction || Technical development
|-
| SATHI friction knee (India) || Weight-activated friction || Limited data available
|}

[[File:Low cost prosthetic limbs.jpg|thumb|Low-cost above-knee prosthetic limbs: ICRC Knee (left) and LC Knee (right)]]

A plan for a low-cost artificial leg, designed by Sébastien Dubois, was featured at the 2007 International Design Exhibition and award show in Copenhagen, Denmark, where it won the [[Index: Award]]. It would be able to create an energy-return prosthetic leg for US [[United States dollar|$]]8.00, composed primarily of [[fiberglass]].<ref>[http://www.indexaward.dk/2007/default.asp?id=706&show=nomination&nominationid=163&playmovie=wmv INDEX:2007 INDEX: AWARD] {{webarchive |url=https://web.archive.org/web/20090202173652/http://www.indexaward.dk/2007/default.asp?id=706&show=nomination&nominationid=163&playmovie=wmv |date=February 2, 2009 }}</ref>

Prior to the 1980s, foot prostheses merely restored basic walking capabilities. These early devices can be characterized by a simple artificial attachment connecting one's residual limb to the ground.

The introduction of the Seattle Foot (Seattle Limb Systems) in 1981 revolutionized the field, bringing the concept of an Energy Storing Prosthetic Foot (ESPF) to the fore. Other companies soon followed suit, and before long, there were multiple models of energy storing prostheses on the market. Each model utilized some variation of a compressible heel. The heel is compressed during initial ground contact, storing energy which is then returned during the latter phase of ground contact to help propel the body forward.

Since then, the foot prosthetics industry has been dominated by steady, small improvements in performance, comfort, and marketability.

With [[3D printing|3D printers]], it is possible to manufacture a single product without having to have metal [[Molding (process)|molds]], so the costs can be drastically reduced.<ref>{{cite news|last=Nagata |first=Kazuaki |url=http://www.japantimes.co.jp/news/2015/05/10/national/science-health/robot-arm-startup-taps-3-d-printers-in-quest-to-make-prosthetics-affordable/ |title=Robot arm startup taps 3-D printers in quest to make prosthetics affordable |publisher=Japantimes.co.jp |date=2015-05-10 |access-date=2016-12-28|newspaper=The Japan Times Online }}</ref>

''[[Jaipur foot]]'', an artificial limb from [[Jaipur]], [[India]], costs about US$40.

===Open-source robotic prosthesis===
{{See also|Open-source hardware|Modular design|3D printing|Thingiverse}}
[[File:Star Wars Bionic hand.jpg|thumb|''Star Wars'' themed "Hero Arm" by Open Bionics]]
There is currently an [[Open-design movement|open-design]] Prosthetics forum known as the "[[Open Prosthetics Project]]". The group employs collaborators and volunteers to advance Prosthetics technology while attempting to lower the costs of these necessary devices.<ref>{{cite web |url=http://openprosthetics.org/ |title=Open Prosthetics Website |publisher=Openprosthetics.org |access-date=2016-12-28 |archive-date=2006-10-04 |archive-url=https://web.archive.org/web/20061004053611/http://openprosthetics.org/ }}</ref> [[Open Bionics]] is a company that is developing open-source robotic prosthetic hands. They utilize 3D printing to manufacture the devices and low-cost 3D scanners to fit them onto the residual limb of a specific patient. Open Bionics' use of 3D printing allows for more personalized designs, such as the "Hero Arm" which incorporates the users favourite colours, textures, and even aesthetics to look like superheroes or characters from ''Star Wars'' with the aim of lowering the cost. A review study on a wide range of printed prosthetic hands found that 3D printing technology holds a promise for individualised prosthesis design, is cheaper than commercial prostheses available on the market, and is more expensive than mass production processes such as injection molding. The same study also found that evidence on the functionality, durability and user acceptance of 3D printed hand prostheses is still lacking.<ref name="Review 3D-printed hand prostheses">{{cite journal |last1=ten Kate |first1=Jelle |last2=Smit |first2=Gerwin |last3=Breedveld |first3=Paul |title=3D-printed upper limb prostheses: a review |journal=Disability and Rehabilitation: Assistive Technology |date=2 February 2017 |volume=12 |issue=3 |pages=300–314 |doi=10.1080/17483107.2016.1253117 |pmid=28152642 |s2cid=38036558 |doi-access=free }}</ref>

==Low-cost prosthetics for children==
{{See also|open-source hardware|3D printing}}
[[File:Artificial limbs for a thalidomide child, 1961-1965. (9660575567).jpg|thumbnail|upright|Artificial limbs for a juvenile [[thalidomide]] survivor 1961–1965]]
In the USA an estimate was found of 32,500 children (<21 years) had a major paediatric amputation, with 5,525 new cases each year, of which 3,315 congenital.<ref>{{cite journal|pmid=1946626|year=1991|last1=Krebs|first1=D. E.|title=Prosthetic management of children with limb deficiencies|journal=Physical Therapy|volume=71|issue=12|pages=920–34|last2=Edelstein|first2=J. E.|last3=Thornby|first3=M. A.|doi=10.1097/01241398-199205000-00033}}</ref>

Carr et al. (1998) investigated amputations caused by landmines for Afghanistan, Bosnia and Herzegovina, Cambodia and Mozambique among children (<14 years), showing estimates of respectively 4.7, 0.19, 1.11 and 0.67 per 1000 children.<ref>{{cite journal|author=Carr, D.B. |year=1998|title=Pain and Rehabilitation from Landmine Injury|url=http://e-safe-anaesthesia.org/e_library/10/Pain_and_rehabilitation_from_landmine_injuries_Update_2000.pdf|volume=6|issue=2|page=91|journal=Update in Anaesthesia}}</ref> Mohan (1986) indicated in India a total of 424,000 amputees (23,500 annually), of which 10.3% had an onset of disability below the age of 14, amounting to a total of about 43,700 limb deficient children in India alone.<ref>Mohan, D. (1986) [http://www.oandplibrary.org/op/1986_01_016.asp A Report on Amputees in India]. oandplibrary.org</ref>

Few low-cost solutions have been created specially for children. Examples of low-cost prosthetic devices include:

===Pole and crutch===
This hand-held pole with leather support band or platform for the limb is one of the simplest and cheapest solutions found. It serves well as a short-term solution, but is prone to rapid contracture formation if the limb is not stretched daily through a series of range-of motion (RoM) sets.<ref name="ReferenceA">Strait, E. (2006) [https://cdn.ymaws.com/www.oandp.org/resource/resmgr/images/resresearch/DevelopingCountries.pdf ''Prosthetics in Developing Countries'']. oandp.org Retrieved 2019-03-11</ref>

===Bamboo, PVC or plaster limbs===
This also fairly simple solution comprises a plaster socket with a bamboo or PVC pipe at the bottom, optionally attached to a prosthetic foot. This solution prevents contractures because the knee is moved through its full RoM. The David Werner Collection, an online database for the assistance of disabled village children, displays manuals of production of these solutions.<ref>{{cite book |last1=Werner |first1=David |title=Disabled village children: A guide for community health workers, rehabilitation workers, and families |date=1987 |publisher=Hesperian Foundation |location=Palo Alto, CA, USA |isbn=0-942364-06-6 |edition=1st |url=https://www.dinf.ne.jp/doc/english/global/david/dwe002/dwe00201.html}}</ref>

===Adjustable bicycle limb===
This solution is built using a bicycle seat post up side down as foot, generating flexibility and (length) adjustability. It is a very cheap solution, using locally available materials.<ref>Cheng, V. (2004) [http://www.ispo.ca/files/bicycle-prosthesis.pdf A victim assistance solution]. School of Industrial Design, Carleton University.</ref>

===Sathi Limb===
It is an endoskeletal modular lower limb from India, which uses thermoplastic parts. Its main advantages are the small weight and adaptability.<ref name="ReferenceA"/>

===Monolimb===
Monolimbs are non-modular prostheses and thus require more experienced prosthetist for correct fitting, because alignment can barely be changed after production. However, their durability on average is better than low-cost modular solutions.<ref>{{Cite journal|last1=Lee|first1=Winson C. C.|last2=Zhang|first2=Ming|date=2005-08-01|title=Design of monolimb using finite element modelling and statistics-based Taguchi method|journal=Clinical Biomechanics|volume=20|issue=7|pages=759–766|doi=10.1016/j.clinbiomech.2005.03.015|pmid=15963612|issn=0268-0033|url=https://eprints.qut.edu.au/2925/1/2925_1.pdf}}</ref>

== Cultural and social theory perspectives ==
A number of theorists have explored the meaning and implications of prosthetic extension of the body. [[Elizabeth Grosz]] writes, "Creatures use tools, ornaments, and appliances to augment their bodily capacities. Are their bodies lacking something, which they need to replace with artificial or substitute organs?...Or conversely, should prostheses be understood, in terms of aesthetic reorganization and proliferation, as the consequence of an inventiveness that functions beyond and perhaps in defiance of pragmatic need?"<ref>Grosz, Elizabeth (2003). "Prosthetic Objects" in ''The State of Architecture at the Beginning of the 21st Century''. pp. 96–97. The Monacelli Press. {{ISBN|1580931340}}.</ref> [[Elaine Scarry]] argues that every artifact recreates and extends the body. Chairs supplement the skeleton, tools append the hands, clothing augments the skin.<ref>{{Cite book|title=The Body in Pain: The Making and Unmaking of the World|last=Scarry|first=Elaine|publisher=Oxford University Press|year=1985}}</ref> In Scarry's thinking, "furniture and houses are neither more nor less interior to the human body than the food it absorbs, nor are they fundamentally different from such sophisticated prosthetics as artificial lungs, eyes and kidneys. The consumption of manufactured things turns the body inside out, opening it up ''to'' and ''as'' the culture of objects."<ref>Lupton and Miller (1992). "Streamlining: The Aesthetics of Waste" in Taylor, M. and Preston, J. (eds.) 2006. ''Intimus: Interior Design Theory Reader''. pp. 204–212. {{ISBN|978-0-470-01570-4}}.</ref> [[Mark Wigley]], a professor of architecture, continues this line of thinking about how architecture supplements our natural capabilities, and argues that "a blurring of identity is produced by all prostheses."<ref>{{cite journal |last = Wigley |first = Mark |title=Prosthetic Theory: The Disciplining of Architecture|journal=Assemblage|issue=15|pages=6–29 |doi=10.2307/3171122 |jstor=3171122|year=1991 }}</ref> Some of this work relies on [[Sigmund Freud|Freud]]'s earlier characterization of man's relation to objects as one of extension.

=== Negative social implications ===
Prosthetics play a vital role in how a person perceives themselves and how other people perceive them. The ability to conceal such use enabled participants to ward off social stigmatization that in turn enabled their social integration and the reduction of emotional problems surrounding such disability.<ref>{{Cite journal |last=Murray |first=Craig D. |date=May 2005 |title=The social meanings of prosthesis use |journal=Journal of Health Psychology |volume=10 |issue=3 |pages=425–441 |doi=10.1177/1359105305051431 |issn=1359-1053 |pmid=15857872}}</ref> People that lose a limb first have to deal with the emotional result of losing that limb. Regardless of the reasons for amputation, whether due to traumatic causes or as a consequence of illness, emotional shock exists. It may have a smaller or larger amplitude depending on a variety of factors such as patient age, medical culture, medical cause, etc. As a result of amputation, the research participants' reports were loaded with drama. The first emotional response to amputation was one of despair, a severe sense of self-collapse, something almost unbearable.<ref name=":8">{{Cite journal |last1=Roșca |first1=Andra Cătălina |last2=Baciu |first2=Cosmin Constantin |last3=Burtăverde |first3=Vlad |last4=Mateizer |first4=Alexandru |date=2021-05-26 |title=Psychological Consequences in Patients With Amputation of a Limb. An Interpretative-Phenomenological Analysis |journal=Frontiers in Psychology |volume=12 |article-number=537493 |doi=10.3389/fpsyg.2021.537493 |issn=1664-1078 |pmc=8189153 |pmid=34122200 |doi-access=free }}</ref> Emotional factors are just a small part of looking at social implications. Many people who lose a limb may have lots of anxiety surrounding prosthetics and their limbs. After surgery, for an extended period of time, the interviewed patients from the National Library of Medicine noticed the appearance and increase of anxiety. A lot of negative thoughts invaded their minds. Projections about the future were grim, marked by sadness, helplessness, and even despair. Existential uncertainty, lack of control, and further anticipated losses in one's life due to amputation were the primary causes of anxiety and consequently ruminations and insomnia.<ref name=":8" /> From losing a leg and getting a prosthetics there were also many factors that can happen including anger and regret. The amputation of a limb is associated not only with physical loss and change in body image but also with an abrupt severing in one's sense of continuity. For participants with amputation as a result of physical trauma the event is often experienced as a transgression and can lead to frustration and anger.<ref name=":8" />

=== Ethical concerns ===

There are also many ethical concerns about how the prosthetics are made and produced. A wide range of ethical issues arise in connection with experiments and clinical usage of sensory prostheses: animal experimentation; informed consent, for instance, in patients with a locked-in syndrome that may be alleviated with a sensory prosthesis; unrealistic expectations of research subjects testing new devices.<ref>{{Citation |last=Hansson |first=Sven Ove |title=Ethical Implications of Sensory Prostheses |date=2015 |work=Handbook of Neuroethics |pages=785–797 |editor-last=Clausen |editor-first=Jens |place=Dordrecht |publisher=Springer Netherlands |language=en |doi=10.1007/978-94-007-4707-4_46 |isbn=978-94-007-4707-4 |editor2-last=Levy |editor2-first=Neil}}</ref> How prosthetics come to be and testing of the usability of the device is a major concern in the medical world. Although many positives come when a new prosthetic design is announced, how the device got to where it is leads to some questioning the ethics of prosthetics.

=== Debates ===

There are also many debates among the prosthetic community about whether they should wear prosthetics at all. This is sparked by whether prosthetics help in day-to-day living or make it harder. Many people have adapted to their loss of limb making it work for them and do not need a prosthesis in their life. Not all amputees will wear a prosthesis. In a 2011 national survey of Australian amputees, Limbs 4 Life found that 7 percent of amputees do not wear a prosthesis, and in another Australian hospital study, this number was closer to 20 percent.<ref>{{Cite web |title=Not everyone uses a prosthesis |url=https://www.limbs4life.org.au/news-events/news/not-everyone-uses-a-prosthesis |access-date=2023-11-27 |website=Limbs 4 life |language=en}}</ref> Many people report being uncomfortable in prostheses and not wanting to wear them, even reporting that wearing a prosthetic is more cumbersome than not having one at all. These debates are natural among the prosthetic community and help us shed light on the issues that they are facing.

==Notable users of prosthetic devices==
* [[Henry William Paget, 1st Marquess of Anglesey]] (1768–1854), [[Lord Uxbridge's leg|whose leg]] was amputated at the Battle of Waterloo
* [[Marie Moentmann]] (1900–74), child survivor of industrial accident
* [[Terry Fox]] (1958–81), Canadian athlete, humanitarian, and [[cancer research]] activist
* [[Oscar Pistorius]] (born 1986), South African former professional sprinter
* [[Harold Russell]] (1914–2002), WWII veteran, Academy Award-winning actor

== Mythological ==
[[Nuada Airgetlám|Nuada]], mythical king loses his arm in battle but is given a silver arm in its place.

[[Vishpala|Visphala]], mentioned in the [[Rigveda]] as losing a leg in battle, but being given "leg of iron" 

== See also ==
{{col div|colwidth=40em}}
* [[Artificial heart]]
* [[Bionics]]
* [[Capua Leg]]
* [[Cybernetics]]
* [[Cyborg]]
* [[Robotic arm]]
* [[Transhumanism]]
* [[Whole brain emulation]]
{{colend}}

== References ==
=== Citations ===
{{Reflist}}

=== Sources ===
{{refbegin}}
* {{cite book |title=A Primer on Amputations and Artificial Limbs |last1=Murdoch |first1=George |last2=Wilson | first2=A. Bennett Jr. |year=1997 |publisher=Charles C Thomas Publisher, Ltd. |location=United States of America |isbn=978-0-398-06801-1 |pages=3–31 }}
* [https://web.archive.org/web/20100909070935/http://www.sportsinjurybulletin.com/archive/biomechanics-running.html 'Biomechanics of running: from faulty movement patterns come injury.' Sports Injury Bulletin.]
* Edelstein, J. E. Prosthetic feet. State of the Art. Physical Therapy 68(12) Dec 1988: 1874–1881.
* [http://www.oandp.com/edge/issues/articles/2002-10_02.asp Gailey, Robert. The Biomechanics of Amputee Running. October 2002.]
* {{cite journal |author1=Hafner B. J. |author2=Sanders J. E. |author3=Czerniecki J. M. |author4=Ferguson J. |year = 2002 | title = Transtibial energy-storage-and-return prosthetic devices: A review of energy concepts and a proposed nomenclature |journal = Journal of Rehabilitation Research and Development |volume = 39 |issue = 1 |pages = 1–11 |pmid=11926321 }}
{{refend}}

== External links ==
{{Wiktionary}}
{{Commons category|Prosthetics}}
* [http://www.fayobserver.com/military/afghan-amputees-tell-their-stories-at-texas-gathering/article_45beb9dd-9c3d-5291-ba43-0aa0664a39be.html Afghan amputees tell their stories at Texas gathering], Fayetteville Observer
* [https://www.pbs.org/newshour/show/can-modern-prosthetics-actually-help-reclaim-sense-touch Can modern prosthetics actually help reclaim the sense of touch?], PBS Newshour
* [https://www.fayobserver.com/news/20111030/a-hand-for-rick-underwater-videographer-rick-allen-overcomes-near-fatal-accident A hand for Rick], Fayetteville Observer
*[https://instanttechblog.com/what-is-prosthetic-limbs-and-its-component/ What is prosthesis, prosthetic limb and its various component] {{Webarchive|url=https://web.archive.org/web/20220718010914/https://www.instanttechblog.com/what-is-prosthetic-limbs-and-its-component/ |date=2022-07-18 }}
*[https://www.inputmag.com/culture/cyborg-chic-bionic-prosthetic-arm-sucks I have one of the most advanced prosthetic arms in the world – and I hate it] by Britt H. Young
*[https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0192094 A systematic review of randomised controlled trials assessing effectiveness of prosthetic and orthotic interventions]
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