ACSM Personal Trainer Certification Practice Exam

What is the primary joint involved during movements of the trapezius muscle?

1. Elbow joint

2. Wrist joint

3. Shoulder girdle

4. Knee joint

The correct answer is: Shoulder girdle

The trapezius muscle is primarily involved in movements associated with the shoulder girdle. This large, triangular muscle extends from the base of the skull down to the mid-back and spans across the shoulder girdle, primarily influencing the movements of the scapulae. Key actions of the trapezius include elevation, depression, retraction, and rotation of the scapula. This muscle plays a critical role in various upper body movements, such as shrugging the shoulders, pulling the shoulder blades together, and facilitating overhead motions. In contrast, the elbow joint, wrist joint, and knee joint do not directly engage the trapezius muscle in their primary functions or movements. The elbow and wrist joints are involved in arm and hand movements primarily driven by the muscles of the upper arm and forearm, while the knee joint is central to movements of the leg. Thus, focusing on the shoulder girdle as the primary joint involved provides a clear understanding of the functional anatomy associated with the trapezius muscle.