Subscapular Nerves

nervi subscapulares

The upper and lower subscapular nerves supply the subscapularis from the posterior cord of the brachial plexus. The lower subscapular nerve also supplies the teres major. They are at risk during posterior cord brachial plexus injuries and during posterior axillary surgery. Testing subscapularis function with the lift-off test and teres major with resisted internal rotation at the side can identify lower subscapular nerve dysfunction.

Region: Shoulder

Anatomical Data

Origin, Insertion & Supply

Origin	Posterior cord of the brachial plexus (C5, C6, C7)

Clinical Relevance

Clinical Notes

Lower subscapular nerve dysfunction produces combined subscapularis and teres major weakness presenting as reduced internal rotation strength with an asymmetric posterior axillary fold (smaller teres major). Distinguishing this from subscapularis tendon tear requires ultrasound or MRI to differentiate neurological from structural pathology.

Pathology

Common Injuries & Conditions

Lower Subscapular Nerve Injury

Combined subscapularis and teres major weakness from brachial plexus or posterior cord injury producing internal rotation weakness and asymmetric posterior axillary fold.