College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which of the following muscles aids in the upward rotation of the scapula?

1. levator scapulae

2. trapezius

3. pectoralis major

4. serratus anterior

The correct answer is: trapezius

The trapezius muscle plays a significant role in the upward rotation of the scapula, particularly through its upper and lower fibers. The upper fibers help elevate the scapula, while the lower fibers assist in pulling the scapula downwards, creating a rotational effect that results in upward rotation when the arm is raised. This coordinated action is essential for a full range of shoulder motion, especially overhead movements. In contrast, the levator scapulae primarily functions to elevate the scapula and does not contribute significantly to upward rotation. Pectoralis major is primarily involved in movements of the humerus, such as adduction and flexion, rather than scapular motion. The serratus anterior does assist in scapular movements, particularly in protraction and upward rotation, but the trapezius is more commonly highlighted as the muscle that significantly aids in the upward rotation of the scapula when considering the overall movement and function of the shoulder girdle.