Inferior subscapular nerve

Inferior Subscapular Nerve

The inferior subscapular nerve is a significant peripheral nerve of the human body that plays a crucial role in the innervation of certain muscles in the shoulder region. It is one of the branches of the brachial plexus, a complex network of nerves that originates from the spinal cord and provides motor and sensory innervation to the arm, forearm, and hand.

Anatomy

The inferior subscapular nerve arises from the posterior cord of the brachial plexus, typically deriving fibers from the C5, C6, and C7 nerve roots. It courses inferiorly along the posterior wall of the axilla to innervate the subscapularis muscle and the teres major muscle, both of which are vital for the movement and stabilization of the shoulder joint.

Innervation

The primary function of the inferior subscapular nerve is to provide motor innervation to the lower part of the subscapularis muscle and the teres major muscle. The subscapularis muscle, being part of the rotator cuff, is essential for internal rotation of the arm at the shoulder. The teres major muscle assists in the adduction and medial rotation of the arm. Through its innervation, the inferior subscapular nerve plays a pivotal role in the complex movements and stability of the shoulder joint.

Clinical Significance

Injury to the inferior subscapular nerve can result in weakness or paralysis of the muscles it innervates, leading to compromised shoulder movement and stability. Such injuries may occur due to trauma, surgical procedures near the brachial plexus, or compression by surrounding structures. Diagnosis of inferior subscapular nerve injury involves clinical examination and may be supported by electromyography (EMG) studies to assess the nerve's functionality.

See Also

• Brachial Plexus
• Subscapularis Muscle
• Teres Major Muscle
• Peripheral Nerve Injury