Subscapular nerves lesions

Causes

• Lesion of posterior cord of brachial plexus.

Symptoms & signs

• Weakness of internal rotation and adduction of humerus.
• Arm might be slightly externally rotated.
• Patient may report difficulty scratching lower back.

Examination

• Test shoulder internal rotation strength: Ask patient to place palm on their belly under xiphoid process and press. Patients with weak internal rotators (subscapularis, teres major) will flex the wrist and adduct and extend instead of internally rotating the shoulder.