Do you have shoulder discomfort when you hop on a bar? The first questions you need to ask yourself is “do I wrap my thumb around the pull up bar or use a suicide grip?”
When an athlete actually wraps their thumb around the bar they are engaging their grip (if I was to ask you to squeeze something as hard as you can, would you wrap your thumb around the object or suicide grip it?)
The simple act of gripping can have a great influence on the shoulder, mainly by increasing rotator cuff muscle activity. One of the main functions of the rotator cuff is to stabilize the shoulder joint. Shoulder joint stability should be a top priority to anyone swinging “aggressively” from a pull-up bar when kipping. Gripping also decreases
So start wrapping your thumb around the bar when kipping. It’s going to feel unnatural and definitely be uncomfortable at first, but your shoulders will appreciate it.