College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which nerve provides motor innervation to the teres major?

1. Thoracodorsal nerve

2. Ulnar nerve

3. Subscapular (lower) nerve

4. Median nerve

The correct answer is: Subscapular (lower) nerve

The teres major muscle is primarily responsible for actions such as shoulder extension, adduction, and internal rotation. The nerve that provides motor innervation to this muscle is the lower subscapular nerve. This nerve arises from the posterior cord of the brachial plexus and specifically innervates both the subscapularis muscle and the teres major. This innervation is crucial for facilitating the muscle's function, which plays a significant role in movement and stabilization of the shoulder joint. Understanding the specific nerve that innervates each muscle is essential for diagnosing and treating conditions related to the shoulder, as well as for effective massage therapy techniques that aim to relieve tension and improve function in that area. While other nerves listed have important roles in innervating different muscles in the shoulder and arm, they do not provide direct motor innervation to the teres major.