The is the buttocks stretch for the piriformis muscle.
To begin, we'll come onto all fours. Bring the affected leg forward; take the foot across and underneath the body so that the affected knee is outside the body, and start sliding the back leg back in space so that your hips lower down to the earth.
Make sure that the pelvis stays level here and you’re not dropping onto one side.
If you feel that it’s uncomfortable to lower your pelvis down, you can use a pillow or a blanket underneath your affected hip. And keep your foot flexed to protect your knee.
Now, if you can lower down to the earth and you feel OK here, consider coming down onto your forearms to take it even deeper.
Now, if at any point you feel any pain, or pinching, or discomfort, come out of it right away and consult a physician before attempting to come into that again.
That is the buttocks stretch for the piriformis muscle.