As you walk, muscles and neurons constantly send information to your brain about where your legs are, where your feet hit the ground, and how hard they push off. Without that feedback, it can be hard to coordinate movement. As a result, amputees who wear prosthetic legs commonly develop gait abnormalities such as shorter strides, slower walking speeds, and standing on tip-toe to swing the prosthetic leg.
"The lack of sensation can affect mobility and quality of life," says Zachary McKinney, a graduate student in biomedical engineering at UCLA. McKinney and his colleagues have been working on a simple feedback system that can be incorporated with almost any below-the-knee prosthetic leg. "Our goal is to improve sensory awareness of the prosthetic."