Action:  Shoulder lateral rotation

Nerves:  Axillary and suprascapular

Skeletal muscles:  Deltoid, infraspinatus, and teres minor

Cutaneous distribution:  None except for the axillary nerve

Neuromuscular deficit:  Weakness/paralysis when rotating laterally at the shoulder joint under resistance. Denervation is accompanied by muscular atrophy, internal rotation of the shoulder, and cutaneous deficit along the distribution of the axillary (superior lateral brachial cutaneous) nerve.

Differential diagnosis:  Weakness/paralysis plus cutaneous deficit along the superior and lateral arm are diagnostic of axillary nerve impairment, because the suprascapular nerve has no distribution in the skin.