Hey all, I'm trying to pinpoint a cause and solution to a recurring problem I have when performing triceps exercises. It seems that towards the end of my workouts I start to have slight pain under arm/above my elbow, normally by the time I'm doing standing tricep extensions, which is usually one of my last exercises.

It feels like a tendon or muscle "popping" on the way back up, sometimes it's a show stopper for the day. It's not the joint. Only happens with one arm. Never had any arm injuries or anything. What could this be??