Because unilateral lower-limb amputation has been associated with secondary impairments such as knee osteoarthritis in the uninvolved limb, a team of researchers hypothesized that, among people who use a lower-limb prosthesis, peak knee internal abduction moment (IAM) and loading rates of the uninvolved limb would be greater with a high-damping prosthetic foot compared with a low-damping prosthetic foot, across walking speeds. The findings from the resultant study suggest that damping properties of prosthetic feet are related to the peak knee IAM and loading rates of the uninvolved limb.
For the study, a cohort of eight healthy young subjects walked in a prosthesis-simulator boot using the experimental feet. Greater first peak IAM (+16 percent in fast speed; +11 percent in slow speed) and loading rates (+11 percent in fast speed) of the uninvolved limb were observed when using the high-damping foot compared to low-damping foot. Within each foot, the first peak IAM and loading rates of the uninvolved limb tended to increase with increased walking speed.
The study is in press in the Journal of Applied Biomechanics.