To perform the Brettzel stretch, start on the ground. Lay on one side, extending your bottom arm and leg straight out. Bend your top leg at the knee over the other at a 90-degree angle and rest it on the ground as you reach behind yourself with your top arm. Grip your bent knee with the bottom hand, pulling slightly to drive your knee into the ground. Bend your bottom leg and grab your foot with your top hand, pulling your heel toward your butt. Finally, release any tension in your neck and allow your head to relax.