"Tricep Dumbbell Kickback" is my favorite exercise to work on triceps but fatigue pain (Not a pain because I am hurt). I can't hold weight with elbow at 90 degree position. The position that I chose to work on triceps is shown in edited picture, also I marked where I feel pain. It started paining before I feel pumped up (worked out) triceps. I do 3 sets/each arm, each sets has 12-10-8 reps, with gradually increasing weight. I take rest for 10-12 seconds between each set, though I want to rest lesser but I am afraid that fatigue pain would not let me complete the next set, so I rest longer.

Question is, this pain is normal for every body builder(expert or beginner) and no alternative to it or is it with me only, I am doing it the wrong way?

![enter image description here](https://i.stack.imgur.com/tdFSq.png)