Control of independent digital flexion and extension has remained an elusive goal in myoelectric prosthetics for upper extremity amputees. We first performed a cadaver study to determine the feasibility of transferring the interossei muscles for each digit to the dorsum of the hand without damaging the neurovascular pedicles. Once this capability was ensured, a clinical case was performed transferring the interossei of the middle and ring fingers to the dorsum of the hand where they could serve as a myoelectric signal for a partial hand amputee to allow individual digital control with a myoelectric prosthesis. Before surgery, it was impossible to detect an independent signal for each interossei; however, after the surgery, signals were reliably detected, which allowed these muscles to serve as myosites for finger flexion using a myoelectric prosthesis and move each digit independently. This concept of salvaging innervated and perfused muscles from an amputated part and transferring them into the more proximal and superficial portion of a salvaged limb has broad applications for improved myoelectric prosthetic control.
Keywords: Amputation; electromyographic signal; interossei muscle transfer; myoelectric control; prosthesis.
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