Isolated paralysis of the serratus anterior muscle: a weight training injury. Case report

Nerve entrapment in athletes

Nerve entrapment syndromes can occur in athletes. The repetitive and vigorous use or overuse of the upper extremity makes the athlete particularly vulnerable to disorders of peripheral nerves. Understanding the clinical signs and symptoms is essential to treatment. The pertinent anatomy, clinical presentation, treatment, and rehabilitation necessary for return to sports for various nerve entrapments have been described. This should enable the physician caring for the athlete to help prevent injury and to guide appropriate treatment, if intervention becomes necessary.

Cause of long thoracic nerve palsy: a possible dynamic fascial sling cause

Long thoracic nerve palsy can result from sudden or repetitive external biomechanical forces. This investigation describes a possible dynamic cause from internal forces. Six fresh cadaveric shoulders (3 female, 3 male, 4 left, 2 right) with full range of motion were systematically dissected to evaluate the anatomic course of the long thoracic nerve. In all specimens a tight fascial band of tissue arose from the inferior aspect of the brachial plexus, extended just superior to the middle scalene muscle insertion on the first rib, and presented a digitation that extended to the proximal aspect of the serratus anterior muscle. With progressive manual abduction and external rotation, the long thoracic nerve was found to "bow-string" across the fascial band. Medial and upward migration of the superior most aspect of the scapula was found to further compress the long thoracic nerve. Previous investigations have reported that nerves tolerate a 10% increase in their resting length before a stretch-induced neuropraxia develops. Previous studies postulated that long thoracic nerve palsy resulted from the tethering effect of the scalenus medius muscle as it actively or passively compressed the nerve; however, similar neuromuscular relationships occur in many other anatomic sites without ill effect. We propose that the cause of long thoracic nerve palsy may be this "bow-stringing" phenomenon of the nerve across this tight fascial band. This condition may be further exacerbated with medial and upward migration of the superior aspect of the scapula as is commonly seen with scapulothoracic dyskinesia and fatigue of the scapular stabilizers. Rehabilitation for long thoracic nerve palsy may therefore benefit from special attention to scapulothoracic muscle stabilization.

Nerve injuries

Sports medicine physicians should be able to recognize and manage peripheral nerve injuries in athletes. Most often, the injury is a result of repetitive microtrauma, linking peripheral nerve injury to other musculoskeletal injuries in athletes. As with other musculoskeletal injuries, rest and a modification of the athlete's regimen often lead to clinical improvement. If the physician is uncertain about the diagnosis, if the athlete develops a rapid worsening of symptoms and signs, or if the athlete is refractory to treatment, a physician who specializes in peripheral nerve injuries should be consulted.

Pectoralis minor transfer in serratus anterior paralysis

Six cases of serratus anterior paralysis were treated by transfer of the pectoralis minor muscle. The results were good in five cases.