Lower-limb proprioception in above-knee amputees.

A proprioception measurement system was designed and constructed to evaluate lower-limb knee joint proprioception in ten above-knee amputees. The system permitted the testing of subjects in a position simulating late swing phase of gait. The threshold for detection of slow passive motion and the ability to reproduce specified lower-limb positions were recorded for the sound and the prosthetic limbs of the subjects. A significant difference was detected between prosthetic and sound limb passive motion detection threshold; however, no difference was found between prosthetic and sound limb passive motion reproduction. This finding suggests the importance of hip joint motion appreciation in the amputees' proprioception of the prosthetic knee joint when these motions are associated. Prosthetic limb passive motion reproduction error decreased with age, suggesting that the amputees may improve their ability to use remaining lower limb proprioceptive mechanisms to compensate for the loss of anatomic knee joint structures.