A Biomimetic Ankle-Foot Prosthesis for Improving Postural Balance in Lower Limb Amputees: A Proof-of-Concept Study

Millions of individuals with lower limb amputations encounter considerable challenges in maintaining postural stability due to limited joint movement in passive prostheses. This instability leads to frequent falls and hinders rehabilitation progress. Current prosthetic control models lack precision in accounting for diverse biomechanical variations, further impacting the efficacy of the rehabilitation process. To address this, we developed a novel biomimetic ankle-foot prosthesis prototype with an external ankle joint control to maintain postural balance. Our biomimetic design utilizes a biomechanically relevant neural control approach, i.e., proportional integral derivative controller, guided by the intact limb trajectories, enabling the prosthesis to mimic natural movement patterns and achieve postural balance during weight-shifting exercises. This approach holds promising potential for enhancing human-prosthetic interaction and ultimately improving rehabilitation outcomes and acceptance of advanced prosthetic technologies by individuals with lower limb amputation.