Development of an Adjustable Prosthetic Ankle-Foot Adapter: A Prototype

Prosthetic ankle-foot systems cannot adapt automatically to changes in shoe heel height. These systems can be altered using changes in alignment to properly orient the roll-over shape of the ankle-foot-shoe system. However, these changes require manual adjustments and, with most systems, require tools to make the adjustments. The use of heel-height-adjustable prosthetic ankle-foot systems may be advised for persons who would prefer to use shoes of different heel heights and who understand the necessary alignment changes needed for switching between these shoes. Further work is needed to examine the consequence of using shoes of different heel heights without changing the alignment of the prosthesis to accommodate these heel heights. The inability of prosthetic ankle-foot systems to adapt is perhaps since these systems have set points that cannot be altered without changes in alignment. Future designs of ankle-foot prostheses could make attempts at systems that can adapt automatically to changes in shoe heel height. This feature could allow persons using prostheses the ability to walk using a variety of shoes (and to walk without shoes) comfortably and without needing manual adjustments of their prostheses. The use of similarly oriented roll-over shapes would presumably yield similar loading moments to the residual limb socket, which may be perceived as a similar comfort level by the prosthesis user. The ability to automatically adjust for different heel heights may also lead to automatic adaptability for walking on different ramped surfaces.