Target muscle reinnervation transhumeral amputation

The figure illustrates an example of target muscle reinnervation in a patient with a transhumeral amputation. The surgical approach may differ for an individual depending upon the remaining anatomy after amputation. In this example, in the anterior view (A), the median nerve was transferred to the short head of the biceps to provide EMG signals for hand closure. Innervation of the musculocutaneous nerve to the long head of the biceps was preserved to provide EMG signals for elbow flexion. The ulnar nerve was transferred to the motor nerve innervating the brachialis muscle (as shown here), which prevents neuroma formation and also functions as another biological amplifier to provide an EMG signal for the wrist motion. In the posterior view (B), the distal radial nerve was transferred to the lateral head of the triceps muscle to provide an EMG signal for hand opening, leaving the long head of the triceps to provide an EMG signal for elbow extension. Ultimately, five muscle targets were available in this patient to control the different prosthetic functions.