Question
About 2 months ago i had some pain shooting down the back of my arm when lying in bed proped on my left arm, it persisted for a week or so, i figured it was a tight muscle and i preceeded to stretch it for a few days, and then one day i realized that the long head of my left triceps had stopped flexing/contracting completly, there was no bruising and no pain, it has not flexed since, i can work out fine, the other two heads seem to have picked up the slack, it happened about two months ago, i have had two doctors tell me that i just have an overdeveloped right arm, which i know is bs, i can straighten my arm as hard as possible and the long head just wont flex, and does not respond when working out.

Answer
Dear Jim,

Sounds like you have one of two problems.  Either you have avulsed (torn) off the long head of the tricep, which means that it would need to be re-attached,(this should create a visible lump on the back of the arm) or you have somehow compromised the nerve supply to the muscle...possibly in the neck at the C7 or C8 nerve roots, but more likely at the terminal branches of the radial nerve that innervate the long head of the tricep.

The only true way to determine is there is a nerve supply problem to the long head is with electrodiagnostic testing such as a nerve conduction velocity test.  This will measure the conductivity of the nerve supply to the muscle, and then it may be possible to actually stimulate a contraction of the tricep.  this would have to be performed by a neurologist, however this test is often limited to large diameter nerves and may not be able to ascertain damage to only one head.

I would suggest that you seek out another opinion,  and make sure that you go to an neurologist or orthopedist who specializes in sports injury only.  You want someone who works exclusively on athletes for the best assessment.

Hope this helps Jim.  I wish you the best of luck.

Respectfully,
Dr. J. Shawn Leatherman
www.suncoasthealthcare.net