Which muscle is NOT part of the rotator cuff?

• A. Supraspinatus
• B. Infraspinatus
• C. Deltoid
• D. Subscapularis

Answer: (C)

The deltoid muscle is not part of the rotator cuff. The rotator cuff is a group of four muscles that are primarily responsible for stabilizing the shoulder joint and allowing for a range of shoulder movements. These four muscles are the supraspinatus, infraspinatus, teres minor, and subscapularis.

The deltoid muscle, while also playing a crucial role in shoulder movement, particularly in arm elevation and abduction, is not categorized as a part of the rotator cuff. Instead, it functions to provide bulk and strength to the shoulder, facilitating larger movements but does not contribute to the stability provided by the rotator cuff muscles.

Understanding the structure and function of these muscles is essential in radiography, particularly when evaluating shoulder injuries or pathologies, as the differentiation can influence both imaging techniques and treatment approaches.