Which muscle is NOT part of the muscle group associated with the shoulder girdle?

The quadriceps muscle is not part of the muscle group associated with the shoulder girdle because it is located in the thigh and primarily functions to extend the knee. The shoulder girdle, which includes the scapula and clavicle, is associated with muscles that support movements of the shoulder, arm, and upper body.

In contrast, the supraspinatus, deltoids, and rhomboids are all integral components of the shoulder girdle muscles. The supraspinatus is responsible for initiating shoulder abduction, the deltoids cover a large area around the shoulder joint and are involved in various shoulder movements, and the rhomboids play a key role in stabilizing the scapulae and assisting in retracting the shoulder blades. Understanding the anatomy and function of these muscle groups is crucial for designing effective workout programs and promoting proper movement mechanics.