Final answer:
The infraspinatus and teres minor are the two rotator cuff muscles that laterally rotate the arm.
Step-by-step explanation:
The two rotator cuff muscles that are lateral rotators of the arm are the infraspinatus and teres minor. These muscles are part of the rotator cuff group which includes the supraspinatus, infraspinatus, teres minor, and subscapularis. The infraspinatus and teres minor specifically assist in the lateral rotation of the arm at the shoulder joint.