Which rotator cuff muscle is likely to be engaged when the client attempts to medially rotate the shoulder using manual resistance?

The subscapularis is the primary rotator cuff muscle responsible for medial rotation of the shoulder. When the client engages in medial rotation while facing resistance, the subscapularis is activated to perform this action. This muscle is situated on the anterior surface of the scapula and plays a crucial role in stabilizing the shoulder joint while facilitating movements like internal rotation.

The other rotator cuff muscles have different primary functions. The supraspinatus is primarily involved in shoulder abduction, aiding in raising the arm. The infraspinatus and teres minor are primarily responsible for lateral rotation of the shoulder. Therefore, their engagement during medial rotation would not be significant. Understanding the specific roles of each rotator cuff muscle is essential for recognizing their actions during different movements like rotation.