Both skull crushers and tricep kickbacks work on our triceps. However, skull crushers will place your triceps under a deeper eccentric stretch compared to kickbacks as they train the muscles in a lengthened position. On the other hand, tricep kickbacks train your triceps at a shorter anatomical position, producing a stronger peak contraction.

The difference is that skull crushers put your triceps under a much deeper eccentric stretch than kickbacks, which naturally means that skull crushers create more muscle damage. Kickbacks, on the other hand, provide your triceps with a far stronger peak contraction than any kind of skull crusher.