Limb Loss

A pilot study comparing standard and osseointegrated above the knee amputees

The purpose of this study is to rigorously compare the gaits of transfemoral amputation subjects who are ambulating in conventional (socket) prostheses with those who have undergone transdermal osseointegration procedures.

Principal Investigators: William Anderst, PhD
Co-Investigators: Mark Goodman, MD and Richard McGough, MD

The motion of the femur and pelvis during a walking trial for a subject using a socket suspension prosthesis.
The motion of the femur and pelvis during a walking trial for a subject that has undergone the osseointegration procedure.

Skin strain in standard above the knee amputees with socket prostheses

Skin health and irritation caused by the socket interface is a common issue among prosthetic limb users. Skin strain is thought to be a contributing factor to these skin issues. The purpose of this study was to assess the surface skin strain within the socket interface of a transfemoral amputees’ prosthetic to identify the timing and areas of high strain during walking.

Our model-based tracking technique was used to track the motion of the residual femur during gait (above). Conventional RSA was used to track steel beads (1-2 mm) placed on the skin of the residual limb.
A finite element model of the skin motion was used to identify regions of high skin strain during gait.
Motion of the residual femur was combined with skin motion to demonstrate motion of the femur relative to the skin.

Objective measurements of socket prosthetics to improve comfort and performance

This study will identify key characteristics of in-socket mechanics that are related to physical function and comfort, and correlate these results to readily available clinical measurements. Femur motion relative to socket, skin strain, and in-socket pressure will be measured using various modalities.

An example of in-socket pressure sensor readings in 4 regions measured during treadmill walking.