Insidious onset of shoulder girdle weakness

Resident's case problem.

An 18-year-old man presented to physical therapy 3 days after insidious onset of painless left shoulder girdle weakness.

Decreased light touch sensation was noted on the lateral left shoulder. In addition, weakness was present with shoulder abduction, flexion, external rotation, and internal rotation. Results of magnetic resonance imaging and radiography of the cervical spine, brachial plexus, and left shoulder were normal, Electromyography and nerve conduction velocity study findings were consistent with axillary nerve palsy. The results of the physical examination and diagnostic studies were most consistent with axillary nerve mononeuropathy, probably caused by traction or pressure due to wearing a pack while hiking or firing a weapon.

With sling protection, limitation of physical activity, and gradual return to progressive resistance exercises, the patient had full return of strength and function 2 1/2 months after onset of symptoms. The differential diagnosis for shoulder girdle weakness should be well understood by physical therapists. This knowledge will help the therapist promptly identify the cause of shoulder girdle weakness and initiate appropriate treatment. If the condition requires further evaluation or treatment by another healthcare provider, prompt identification of pathology will allow appropriate timely referral.