3. Tighten the glutes and core more
Using the hips means engaging the glutes, large powerful muscles, consisting of gluteus maximus muscle (considered to be one of the strongest muscles of the human body), gluteus medius muscle, gluteus minimus muscle and tensor fasciae latae muscle. They enable us to bend and straighten the hips and produce the explosive jumping power, or in our case, the explosive “kipping” power.
Besides keeping our spine stabilized and our movement under control, core’s task is also to generate more power within the movement. Tight core will enable you to produce a higher power when kicking down and up with your legs during pull ups.
4. Move elbows behind the back
Don’t allow your neck to break (or your head to fall back at the top of the movement). As Carl Paoli says keep it in a neutral position. At the finish position elbows go behind the back (pull them all the way back) which allows chest to touch the bar.