Final answer:
Humerus fractures can damage nerves in the shoulder and upper limb. The axillary, radial, median, and ulnar nerves are commonly injured in humerus fractures.
Step-by-step explanation:
Humerus fractures, proximally to distally, follow the 'ARM'. When the humerus fractures, it can injure four major nerves associated with different regions of the humerus and the upper limb. These nerves are the axillary nerve, radial nerve, median nerve, and ulnar nerve. The axillary nerve innervates the deltoid and teres minor muscles, the radial nerve innervates the triceps and muscles of the forearm, the median nerve innervates the muscles of the anterior forearm, and the ulnar nerve innervates the muscles of the hand.