I remember the first time I really got a sense for “opening and closing” my joints. We were on a qigong retreat and the person who was helping me probably spent 20 minutes “pulsing” my wrist, so that the fluids in the joint were moving in a smooth, even way, alternately creating more and less space between the bones. When you pulse, you’re manipulating the fluid flows inside your body so that the spaces inside your body compress and expand.