Technology Might Help Amputees Gain Better Mobility

A researcher at the Colorado School of Mines, Golden, is using the same technology used to reproduce realistic movements for animated films and the video-gaming industry to analyze gait, which may lead to a better understanding of mobility in people with lower-limb amputations.

Recently, Anne Silverman, PhD, assistant professor of mechanical engineering, investigated lower-limb mechanics in individuals with an amputation. The 24 subjects she included-a little more than half of whom were amputees-had small, reflective spheres attached to their feet, ankles, shins, knees, thighs, and hips. High-speed motion-capture cameras then tracked the movement of the spheres, which allowed Silverman to characterize human-body motion.

After combining data from motion-capture and ground-force measurements, Silverman was able to calculate the net power generated and absorbed at each joint, and so better understand how individuals with an amputation compensate during walking in the absence of a biological ankle. Her findings showed how little the intact leg was used by many subjects to compensate, and how much of the heavy lifting is done by hip muscles high in the amputated leg, especially when walking at faster speeds. She also attached electrodes to her subjects' legs to measure electrical activity in their muscles.

By combining this electromyography data with other biomechanical measurements, Silverman generated three-dimensional (3D) walking simulations, which can be used to understand the roles of individual muscles and prosthetic devices in whole-body movements.

Silverman said that she hopes her work will contribute to technologies that can be applied in a clinical setting, such as improving the long-term mobility of individuals with lower-limb amputations.

Editor's note: This story has been adapted from materials provided by the Colorado School of Mines magazine Mines.