Do this exercise on your hands and knees. Keep your knees under your hips and your hands under your shoulders.
Relax your belly (abdominal) and buttocks muscles, lift your head, and let your back sag. Be sure to keep your weight evenly distributed. Don’t sit back on your hips.
Hold for
Return to starting position.
Tuck your head and lift (arch) your back.
Hold for
Return to starting position.
Repeat