Finding the perfect prosthetic fit - Sanders UW Research Labs

The muscles and tissues in arms and legs change throughout the day. They warm up, cool off, stiffen, swell or constrict based on things like activity level, environment and age.

But a prosthetic leg does not change. People who rely on them must make manual adjustments throughout the day — usually by adding or removing padding within the socket of the prosthesis. This can be a cumbersome process in public, or when wearing certain clothing. Skipping adjustments can lead to pain or limit mobility.

University of Washington Professor Joan Sanders and her team are creating a new type of prosthetic leg: one that automatically adjusts its fit throughout the day. Their latest prototype alters its fit without the need for adjustments to padding or user action. It detects in real time how well the prosthesis socket and amputation site are fitting and responds by automatically changing the size of the socket.

Test results with volunteers are so promising that the researchers hope to eliminate the need to add or remove padding throughout the day.