Which of the following muscles is not targeted during the posterior shoulder ball roll?

The correct choice identifies the supraspinatus muscle as the one not targeted during the posterior shoulder ball roll. The posterior shoulder ball roll primarily focuses on the muscles involved in posterior shoulder stabilization and rotator cuff function, specifically engaging the teres major, infraspinatus, and rhomboid muscles.

The teres major aids in the stabilization of the shoulder joint and is often engaged during movements that involve the retraction and rotation of the shoulder. The infraspinatus, part of the rotator cuff group, plays a critical role in external rotation and stabilization of the humeral head within the glenoid cavity. The rhomboids, located between the scapulae and the spine, assist in retracting the scapulae and therefore are also involved in this exercise.

In contrast, the supraspinatus, while being a rotator cuff muscle, is primarily responsible for initiating abduction of the arm and is more involved in movements that lift the arm overhead rather than those that engage the posterior aspect of the shoulder. Therefore, it is not specifically targeted during the posterior shoulder ball roll, making it the correct answer in this context.