Oh .. what was your type of injury ??
repetitive ?
did they do any x ray or MRI to check neck/c spine??

c spine injury can affect arms as well as a repetitive motion injury called thoracic outlet syndrome {TOS}

I have a mild case of RSI/TOS.
here's our info sticky from the TOS forum- you might look thru the first post and see if any of the symptoms fit for you.
http://neurotalk.psychcentral.com/thread84.html