Which muscle is NOT involved in external rotation of the shoulder?

The latissimus dorsi is not involved in external rotation of the shoulder. This muscle primarily functions to extend, adduct, and internally rotate the shoulder joint. Its role is largely centered around movements that bring the arm closer to the body or rotate it inward, rather than rotating it outward.

In contrast, the teres minor and infraspinatus are both part of the rotator cuff and are specifically responsible for facilitating external rotation of the shoulder. Additionally, the supraspinatus, while primarily known for its role in arm abduction, also contributes to stability and overall shoulder function but does not play a significant role in external rotation. This highlights the distinct functional roles different shoulder muscles play in movement and stabilization.