Soreness in the arm is not necessarily a nerve problem.
The arm is an anatomical structure located below the shoulder joint and above the wrist joint. Soreness in the arm refers to soreness and swelling as well as painful sensations in the nerves, muscles or joints of this anatomical structure, some of which are neuralgic, usually due to injury to the brachial plexus. Other causes include over-exercise, trauma, fasciitis etc.