This is a relatively common complaint, usually experienced by people who habitually use a computer for their work.
Many times, it is an issue related to an entrapment or impingement of nerves located in the SCALENE muscles on either side of the neck. It also could be related to overly hypertonic (tight) muscle fibers in the upper or lower arm.
It is a condition that is highly resolvable, and relief is usually felt after one session. If you would like further information, please contact me at my office (727) 584-4279 ....or by email listed here. Thank you.