National Certification Board for Therapeutic Massage & Bodywork (NCBTMB) Practice Exam

Which ligament is key in the stability of the shoulder joint?

1. Coracoacromial ligament

2. Glenohumeral ligament

3. Transverse humeral ligament

4. Acromioclavicular ligament

The correct answer is: Glenohumeral ligament

The glenohumeral ligament plays a crucial role in maintaining the stability of the shoulder joint, which is one of the most mobile joints in the body. This ligament consists of three bands that run from the glenoid cavity of the scapula to the humeral head. Due to the shoulder's significant range of motion, it faces a higher risk of instability and dislocation. The glenohumeral ligaments help to provide static stability by reinforcing the joint capsule and limiting excessive movements, especially in glenohumeral abduction and external rotation. In contrast, while the other ligaments mentioned contribute to shoulder stability, they do so in indirect or more specialized capacities. The coracoacromial ligament primarily forms an arch over the shoulder, protecting it from superior dislocation but not directly stabilizing the joint itself. The transverse humeral ligament is more involved in keeping the tendon of the biceps brachii in place within the bicipital groove, and the acromioclavicular ligament supports the acromioclavicular joint but does not directly stabilize the glenohumeral joint. Thus, the glenohumeral ligament is essential for shoulder stability, particularly in dynamic movements that place stress on the joint.