What is it?
The suprascapular nerve arises from the branches of the C4 - C6 spinal nerve roots located in the neck. This nerve innervates the supraspinatus and infraspinatus muscles, which contribute to shoulder abduction and external rotation. The suprascapular nerve supplies sensation to several shoulder structures including ligaments, acromioclavicular (AC) joint, and the glenohumeral joint itself.
A suprascapular nerve injury typically occurs due to compression or traction. A rotator cuff pathology leads to suprascapular nerve dysfunction and vice versa. Although suprascapular nerve dysfunction is relatively uncommon, usually on 2-4% of all shoulder pain, the condition is present in up to 8% of patients with a full rotator cuff tear.
Clinical Presentation
Suprascapular neuropathy is typically unilateral and affects the dominant side more frequently. The clinical presentation includes posterior and superior shoulder pain and weakness. Patients may complain of increased symptoms when the shoulder is moved across the body in adduction and internal rotation. Overhead activity may increase symptoms as well.
Clinical evaluation may demonstrate tenderness to palpation over the suprascapular notch, which is located deep and posterior to the AC joint, between the spine of the scapula and clavicle. Chronic cases may show palpable atrophy of the supraspinatus or infraspinatus muscles.
Diagnosis
EMG testing provides the most definitive diagnosis. Plain film radiography, such as an x-ray, may be used to rule out any bony pathology. An MRI also has the ability to rule out compressive pathology. Ultrasonography is an alternative imaging option for suprascapular neuropathy.
Management
Treatment typically includes rest and the avoidance of activities that place sustained and repetitive stress on the nerve. Patients should avoid excessive scapular protraction, cross body adduction, and overhead movements.
Conservative management can and should provide the most benefit. However, exercises that cause sustained stretch of the suprascapular nerve is not recommended.
Medical alternatives include steroid injections and surgical decompression in cases of persistent ongoing symptoms post conservative care or muscle atrophy. Suprascapular nerve decompression typically relieves pain however, return to normal muscle mass and strength is less predictable.