Which muscles actively resist excessive anterior translation of the glenohumeral joint (GHJ)?

• A. Supraspinatus and Subscapularis
• B. Teres Major and Infraspinatus
• C. Infraspinatus and Teres Minor
• D. Deltoid and Latissimus Dorsi

Answer: (C)

The infraspinatus and teres minor play a crucial role in stabilizing the glenohumeral joint, particularly in resisting excessive anterior translation. These muscles are part of the rotator cuff group, which is essential for maintaining the stability of the shoulder during movement.

The infraspinatus and teres minor are positioned posterior to the shoulder joint and assist in external rotation. This external rotation helps to counteract any excessive anterior movement of the humeral head, as the shoulder is designed to maintain the head of the humerus in the glenoid cavity during arm motions. Their ability to engage and exert a stabilizing force directly supports the joint, reducing the likelihood of anterior displacement.

Understanding the biomechanics of these muscles is vital for recognizing how they contribute to shoulder stability. When they are properly functioning, they can effectively resist forces that would otherwise lead to an unstable shoulder, especially during activities that require overhead motion or when the arm is in a forward position.