I’m at my tennis club and my friend Kelly is going to be a model. I’m going to show you how you can loosen the shoulder muscles. Simply grab the top of the shoulder with curled fingers and shake it back and forth. Move between the neck and the shoulder bone.
I think I do have a strong thumb by now but I was really hooking my thumb and curling my fingers. That’s why Kelly thought I had a very strong thumb. So make sure to hook your thumb to protect the base of the thumb and curl your fingers for more pressure.