Engineers have developed a lightweight, motorless device that can be attached to an ankle foot orthosis (AFO) and aid stroke patients in their rehabilitation, improving their walking and preventing falls.
Stroke patients commonly experience paralysis as a result of damage to the brain, which can significantly affect their ability to walk.
Insufficient knee bending, or knee flexion, during walking leads to difficulty clearing the lower toe and can cause patients to fall. To overcome this, patients frequently hip hike on the affected side, a process by which the patient elevates one side of their hip to move their foot. This makes patients’ walking movement awkward, contributing to decreases in their motivation to continue their rehabilitation, a media release from Tohoku University notes.
Comprised of Professor Shin-Ichi Izumi and Associate Professor Dai Owaki from Tohoku University’s Graduate Schools of Medicine and Graduate School of Engineering, along with Mr. Takeo Nozaki and Dr. Ken-ichiro Fukushi from NEC Corporation, the research group created a device which gives the ankle greater push-off power using a spring-cam mechanism.
How This Adds Push-Off Power
The elliptical shaped cam rotates in conjunction with the AFO, pushing against the spring. The resultant reactive force from the spring generates significant ankle push-off power.
The research group conducted clinical experiments on 11 stroke patients with paralysis on one side of the body, demonstrating that the device generated greater ankle power. This in turn aided knee flexion while the affected foot was in the swing phase of walking — ie, when the foot is raised in the air.
“Our device will pave the way for positive impacts on the rehabilitation of stroke patients. It will prevent falls and make patients feel more confident in their walking abilities.”
— Associate Professor Dai Owaki from Tohoku University’s Graduate Schools of Medicine and Graduate School of Engineering
[Source(s): Tohoku University, Science Daily]