Abstract
The gait of elderly amputees is less stable than healthy elders due to his/her amputation. We developed the new prosthetic foot to increase the stability of the prosthetic gait pattern, especially to reduce the lateral instability. In this paper the evaluation with three parameters about the lateral instability of the gait is described. One is the lateral displacement of Center of Gravity, it's traditional theorem, and the other are Lyapnov Exponents of COG lateral displacement pattern, it's means of reproductive of the displacement pattern, and External Fall Moment at prosthetic side stance. In most cases these parameters revealed the reasonable advantage of the the new prosthetic foot, however the elder amputees prosthetic gait tended to be irregular. It might be necessary to evaluate by multiple parameters including subjective evaluation and measuring with the prosthetist's eye.
