I have this pain in my upper left arm when I reach back, lift something more than a few pounds or lift my arm in the air. I think it is my tricep that is hurting. I've had it a few weeks now, off and on (mostly on). The weird thing is that it is my left arm and I am totally right handed. I'll go to the clinic at my school soon, but I just wanted some feedback. I cannot think of anything that would have done to hurt my arm this way. MAYBE if it were my right arm I could say it was from overuse, but my left arm... no! Thanks in advance.