when i was doing skullcrushers with 120 lbs, something felt quite strange in my left tricep.....it was not a proper feeling, it was like a kind of sharp pain when my arm went down all the way so i stopped the exercise. My left tricep still feels funny- i have a feeling that it could have gotten worse if i kept on doing the exercise, but i am glad i stopped short as i could have got an injury if i kept at it.
What could this be? it feels a little odd when i move my arm back and forth..... never really had to stop an exercise before because of this... But it doesn't hurt too much, sometihng just told me to stop the exercise