Arm Medial and Lateral Rotation

Medial rotation of the arm or humerus can best be seen when the elbow is flexed and the hand is moved toward the midline.

Muscles: subscapularis, latissimus dorsi, teres major, pectoralis major, anterior fibers of deltoid.

With the elbow flexed, lateral rotation moves the hand away from the midline.

Muscles: infraspinatus and teres minor, posterior fibers of deltoid.