Effect of triceps function on the brachioradialis transfer in quadriplegia

Fifteen patients with traumatic quadriplegia who had transfer of the brachioradialis to the flexor pollicis longus were evaluated to determine the influence of triceps function on pinch strength. Pinch was measured with the elbow free and with the elbow locked at 90 degrees in an orthosis that served as an external means of blocking elbow flexion in those patients with impaired triceps strength. Those patients having two foot-pounds or less elbow extension torque had an average pinch of 1.20 kg without elbow immobilization. With the elbow immobilized, pinch strength increased 153%, averaging 3.04 pounds. Those patients having more than two foot-pounds elbow extension torque had an average pinch of 4.08 pounds with the elbow free and pinch strength was not improved by immobilization in the orthosis. The absence of triceps function significantly decreases the effectiveness of the brachioradialis when used to motor a tendon transfer. Surgical procedures, such as posterior deltoid to triceps transfer, which provide active elbow extension can be expected to significantly increase the pinch strength supplied through the brachioradialis transfer in patients without voluntary elbow extension.