UC Santa Barbara

Foot drop is a gait disorder characterized by weakness in the muscles that lift the foot. As a result, the foot tends to scuff the ground during the swing phase of gait. Previous work has demonstrated a treadmill that lowers one side of the tread while the affected foot is swinging forward will prevent scuffing. Preliminary results suggest that preventing scuff during swing can improve the biomechanics and rhythmicity of gait in populations with foot drop. However, the device is expensive and can only be used in the lab. Here we present a wearable passive assistive device in the form of a shoe that mimics the effects of the treadmill. Instead of eliminating contact with the ground, like the treadmill does, the shoe instead substantially reduces the scuffing forces through the use of low friction material on the sole. Critically, for traction during the stance phase of gait, the low friction material can retract into the shoe when the weight of the user is on the shoe. Compared to the treadmill, the shoe can be made for a fraction of the price, is more accessible for personal use, and can improve the daily lives of those with abnormal and impaired gait patterns. This paper presents the iterative design process of Cadence, as well as a feasibility study done with four adults with foot drop due to various neurological injuries. Results of the study show that the shoe immediately improves gait mechanics, speed over ground, and efforts of walking. All of the participants preferred walking in Cadence compared to walking in their normal shoes and other assistive devices. This initial study opens the door to future study for direct assistance and rehabilitative effects.