ACSM Personal Trainer Certification Practice Exam 2025 - Free Personal Trainer Practice Questions and Study Guide

The overhead shoulder press primarily involves the action of shoulder abduction, where the arms move away from the body in an upward direction. This exercise engages several key muscles, primarily the deltoids, which are responsible for the movement of the shoulder. During the press, as the weight travels upward, the shoulders are lifted and stabilized, emphasizing the abductors in the shoulder region.

Shoulder abduction is essential in this movement because it allows for a full range of motion when lifting weights overhead, ensuring effective training of the shoulder muscles. The engagement of additional support muscles, such as the triceps and core, aids in the stability and control of the movement, making shoulder abduction a fundamental aspect of the overhead press.

The other options, such as elbow extension, shoulder flexion, and shoulder adduction, are movements that do not align with the biomechanics of the overhead shoulder press. While elbow extension occurs as the arms push the weight overhead, it is not the main action of the exercise itself; rather, it serves as a supporting movement. Similarly, shoulder flexion describes a different motion where the arms move forward and upwards but does not specifically apply to the overhead press. Lastly, shoulder adduction refers to bringing the arms back towards the body, which