Article

This article describes the development of a prototype prosthetic ankle-foot
system that passively adapts to surface slopes on each step of walking.
Engineering analyses were performed to design the cam clutch and clutch
engagement and disengagement mechanism. The prototype was tested by a veteran
with a unilateral transtibial amputation. Kinematic and kinetic data were
recorded while the subject walked on a treadmill at slopes ranging from -10
degrees to +10 degrees. After each slope condition, the subject rated his level
of exertion and socket comfort. The subject reported increased comfort and
reduced exertion for downhill slopes when using the prototype compared with his
usual prosthesis. The subject also expressed that when walking downhill on the
prototype, it was the most comfortable he has ever been in a prosthesis. The
prosthetic ankle torque-angle relationship shifted toward dorsiflexion for uphill
and toward plantar flexion for downhill slopes when using the prototype,
indicating slope adaptation, but this effect did not occur when the subject
walked with his usual prosthesis. The prototype also demonstrated late-stance
plantar flexion, suggesting the potential for storing and returning more energy
than standard lower-limb prostheses.

Langue : ANGLAIS