ACSM Personal Trainer Certification Practice Exam

Which muscle is responsible for retraction and downward rotation of the scapula?

1. Triceps brachii

2. Rhomboids

3. Pectoralis minor

4. Erector spinae

The correct answer is: Rhomboids

The rhomboids are primarily responsible for the retraction and downward rotation of the scapula. Located between the scapulae and the spine, they play a crucial role in stabilizing the shoulder girdle. During activities that involve pulling the shoulders back, such as rowing or certain types of strength training, the rhomboid muscles contract to draw the scaps closer together (retraction) and assist in rotating the scapula downward, which is essential for maintaining proper shoulder function and posture. In contrast, the triceps brachii is primarily involved in elbow extension and does not contribute to scapular movement. The pectoralis minor, although involved in scapular movements, primarily assists in protraction and downward rotation but does not perform retraction. The erector spinae muscles are mainly involved in spinal extension and stabilization, playing no direct role in the movement of the scapula. Thus, the rhomboids are specifically positioned and functionally adept at executing the desired actions described in the question.