Electromyographic analysis of brachioradialis to flexor pollicis longus tendon transfer in quadriplegia.

Electromyography was done in patients at the C6 level of quadriplegia after transfer of the brachioradialis to the flexor pollicis longus to restore lateral pinch and transfer of the posterior deltoid to the triceps to restore elbow extension. The relationship of the integrated electromyogram to pinch force during a graduated isometric contraction enabled characterization of the motor recruitment pattern. After tendon transfer, the pattern of the electromyographic response for the brachioradialis was the same as in the flexor pollicis longus in normal subjects, and the posterior deltoid after transfer to the triceps fired synergistically with the brachioradialis. These findings indicate reeducation of transferred muscles occurred after surgery and that they functioned as active primary motors.