There is a thing called "double crush" that can happen, usually with thoracic outlet syndrome {TOS}.
you get upper back, neck, shoulder, arm, hand symptoms of TOS {tightness, spasms and/ or nerve pain}
plus definite cubital {ulnar}and/or carpal tunnel symptoms.
here's a link to our TOS forum and RSI {subforum}there -
http://neurotalk.psychcentral.com/forum24.html