Peripheral nerve lesions are uncommon but serious injuries which may delay or preclude an athlete’s safe return to sports. Early, accurate anatomical diagnosis is essential. Nerve lesions may be due to acute injury (e.g. from a direct blow) or chronic injury secondary to repetitive micro-trauma (entrapment). Accurate diagnosis is based upon physical examination and a knowledge of the relative anatomy. Palpation, neurological testing and provocative manoeuvres are mainstays of physical diagnosis. Diagnostic suspicion can be confirmed by electrophysiological testing, including electromyography and nerve conduction studies. Proper equipment, technique and conditioning are the keys to prevention. Rest, anti-inflammatories, physical therapy and appropriate splinting are the mainstays of treatment.
In the shoulder, spinal accessory nerve injury is caused by a blow to the neck and results in trapezius paralysis with sparing of the sternocleidomastoid muscle. Scapular winging results from paralysis of the serratus anterior because of long thoracic nerve palsy. A lesion of the suprascapular nerve may mimic a rotator cuff tear with pain a weakness of the rotator cuff. Axillary nerve injury often follows anterior shoulder dislocation.
In the elbow region, musculocutaneous nerve palsy is seen in weightlifters with weakness of the elbow flexors and dysesthesias of the lateral forearm. Pronator syndrome is a median nerve lesion occurring in the proximal forearm which is diagnosed by several provocative manoeuvres. Posterior interosseous nerve entrapment is common among tennis players and occurs at the Arcade of Frohse — it results in weakness of the wrist and metacarpophalangeal extensors. Ulnar neuritis at the elbow is common amongst baseball pitchers.
Carpal tunnel syndrome is a common neuropathy seen in sport and is caused by median nerve compression in the carpal tunnel. Paralysis of the ulnar nerve at the wrist is seen among bicyclists resulting in weakness of grip and numbness of the ulnar 1.5 digits.
Thigh injuries include lateral femoral cutaneous nerve palsy resulting in loss of sensation over the anterior thigh without power deficit. Femoral nerve injury occurs secondary to an iliopsoas haematoma from high energy sports. A lesion of the sciatic nerve may indicate a concomitant dislocated hip.
Common peroneal nerve injury may be due to a direct blow or a traction injury and results in a foot drop and numbness of the dorsum of the foot. Deep and superficial peroneal nerve palsies could be secondary to an exertional compartment syndrome. Tarsal tunnel syndrome is a compressive lesion of the posterior tibial nerve caused by repetitive dorsiflexion of the ankle — it is common among runners and mountain climbers. Morton’s interdigital neuroma is common amongst dancers and usually responds well to a metatarsal pad.
Prophylactic measures are only modestly successful. Fortunately, the vast majority of these injuries are transient and respond well to conservative therapy. It is the exceptional injury that becomes permanent or requires surgical intervention. However, early recognition and treatment are vital to prevent associated morbidity of these rare but serious injuries.