To do this exercise you will need a mat and a soft ball. Start by lying on your side with your bottom hip on the soft ball. Your knees will be bent and your heels should be lined up with the pelvis. Inhale into the back of the ribcage as you internally rotate the hip and lift the top foot. Exhale as you return to neutral. Repeat 8-10 times.
Things to think about
This exercise can provide a great tension free stretch to the Piriformis. It is a great way to allow your body to find release without pain in the pelvis.
As always with any rotation exercise it is important to allow the hips to remain stacked and the ribs to be connected to the pelvis. Often the ribcage will try to fall forward when you lift the top foot.