Spine-health explained: “This stretch affects the hip flexor muscles, which attach to the pelvis and can impact posture if too tight.”
The fourth stretch recommended is the “piriformis musice stretch” – again, you start by lying with your back to the floor.
With knees bent and both heels on the floor, cross one leg over the other, resting the ankle on the bent knee.
Then gently pull behind the knee (the one that has its foot to the floor) towards you until a stretch is felt in the buttock.