Movement: Lie on your back on a padded mat of floor. Place one leg over the other, right above the knee on the lower thigh. Now, using either a towel, a stretching band or your hands, grasp the bottom leg, and - with your back flat and without hyperextending - slowly pull the knee of this leg closer to your chest. Keep the top leg fixed and you should feel a stretch in the hips. Go as far as your range of motion will comfortably allow.
Repetitions: Hold for the full prescribed time on one side, then switch sides and repeat. This counts as one set.