According to NASM’s Essentials of Corrective Exercise Training the dynamic stabilizers of the “glenohumeral joint is dependent on the musculature that surrounds the joint, including the rotator cuff and scapular stabilizers.”
The key muscles associated with the shoulder are:
4. Teres major and minor
6. Pectoralis major and minor
7. Latissimus dorsi
10. Levator scapulae
The static stabilizers “include such structures as the glenoid labrum and the glenohumeral joint capsule consisting of two major ligaments, the middle and inferior glenohumeral ligaments.
“The inferior ligament is divided into three sections:
1. The anterior-inferior
2. The axillary pouch
3. The posterior-inferior glenohumeral ligaments.”
The above three ligaments limit motion and provide functional stability towards the end range of glenohumeral motion.
“The complex inferior glenohumeral ligament is the primary stabilizer against anterior translation of the humeral head. The anterior and posterior portions of this ligament help stabilize the joint by becoming taught in extreme ranges of internal and external rotation and are often injured with repetitive use in these positions. However, in mid ranges of shoulder motion, the above mentioned ligaments are relatively lax, and the joint must rely heavily on the musculature that surrounds the joint for dynamic stability.”
The scientific sources the NASM utilize in support of what is written in their text are:
1. Terry G, Chopp T, Functional anatomy of the shoulder. J Athl Train 2000:35:248-55
2. Moore KL. Clinically Oriented Anatomy, 3rd ed. Baltimore, MD; Williams & Wilkins; 1992.