Pinch like pain one two places while doing one arm pull ups (i performed the first one well, on doing it for the second time while I was almost up I felt sudden pain and pull on nerve maybe or could be muscle on forearm), after a few min couldn't feel it much though. Is it something serious or should it be ok with rest? Just to let you know I do workout regularly and I have been performing pull ups with weights since past few months which haven't caused me any problems till now. My most recent was pull ups with 30 kg add on for which I did 6 reps).