Several reasons: There are several reasons why this can happen. The most important is do you have a pinched nerve in your neck. If the nerve is pinched it cannot send signals to the muscle and it will not increase in strength. If you are having neck pain or shooting pains in that arm you should see a doctor and have this checked.
Answered 6/21/2014
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A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
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