Agonist-Antagonist Myoneural Interface for Functional Limb Restoration After Transtibial Amputation

This study involves the functional testing of a new lower extremity prosthesis by healthy, active participants with fully healed transtibial (below knee) amputations. The study design calls for an experimental group of eleven participants who received two agonist-antagonist myoneural interfaces (AMIs) that were surgically constructed during a modified transtibial amputation procedure, and a control group of eleven matched participants who received standard transtibial amputations. The study protocol involves one or more of the following activities: 1. Collection of electromyography (EMG) data from participants' lower limbs to characterize muscle activation and create maps specific to individual participants, 2. Investigation of participants' capabilities to use a new lower extremity prosthesis that is designed to allow independent actuation of the ankle and subtalar joints, and offers EMG-modulated control over prosthetic joint position and stiffness, and 3. Exploration of AMIs as a means of communicating information between the participant and the new prosthesis using an experimental system involving EMG, functional electrical stimulation, and ultrasound. The hypothesis is that transtibial amputations involving AMIs can offer improved motor control of the new prosthesis while also enabling proprioceptive sensation (perception of the position, movement, and torque of the affected limb and prosthetic joint). The AMIs are expected to improve voluntary prosthetic control, improve prosthetic terrain adaptations, and offer new possibilities for bi-directional communication across the human-device interface.