In 25-30% of patients, only the upper roots of the brachial plexus (C56 or C567) are affected while the lower roots are partly injured or spared. In such cases, the patient loses power in the shoulder and the elbow while the movements of bending and straightening of the fingers are retained. Function in the shoulder and elbow can be restored in a large percentage of cases (80%) by means of nerve transfers or nerve grafting from available root stumps in the neck. Hence, such patients are more likely to regain almost full use of the affected upper limb.

The retained function in the lower roots (C8T1 and ulnar nerve) implies that an additional donor of growing nerve ends is available. Professor Christophe Oberlin of Paris showed that 10% of fibers of the ulnar nerve could be safely transferred to the biceps in the arm (Journal of Hand Surgery 1994) without producing any deficit in the hand. The biceps function is regained rapidly (4-6 months) in 80% of suitable patients.

As a result, other nerve transfers (spinal accessory and intercostal nerves) can be deployed for restoration of shoulder function and elbow extension. In such patients with retained hand functions, diverting the intercostal nerves to the triceps muscle can facilitate reaching out for objects.