The hand

The structure of the human hand evolved from the fin of earliest fish, adapted to be a foot, then a brachiator and finally a manipulator. Evolution has created hands that are very capable, this is achieved by using a considerable proportion of the central nervous system to control human hands. The design of a prosthetic replacement is complex with many different factors to be considered to make the device useful to the operator. The means to control the hand must be designed to employ actions that the user can perform easily. It is useful to measure the function of a design to assist in prescription of routine devices and to be able to ensure that changes or new designs make a difference to the lives of the users. It is not easy to objectively measure function and it requires careful design of an assessment tool. Earlier tools were able to measure the mechanical or abstract functional properties of the design. Only when its use in the field can be measured objectively can the real use prosthetic hands are put to, be tested. New measurement tools are being developed to make such assessments. Two of the pioneers are interviewed: Alix Chadwell and Adam Spiers. The Cybathlon was created to encourage engineers and clinicians to work together to find better solutions to the problems of designing effective prosthetic limbs. It did so by posing challenges for different devices and is set in a competitive arena. Its first competition was in 2016.