Supine Knee Tucks with Stability Ball

How to: Lay flat on your back, placing a 55cm ball between your lower legs. Squeeze the ball using your adductors (inner thighs) and slowly raise and lower the ball from the floor, drawing your knees to your chest.

Compensations: Watch for arching of the lower back, pushing the abdominals outward and rounding or elevating of the shoulders.