Stability Ball Single Leg Hamstring Curl
Once you master the stability ball hamstring curl, you should try the single leg variation.
Lie on your back on a mat, placing your lower heels on the top of the stability ball. Your feet should be lined up with your hips and your toes pulled slightly toward the ceiling. Contract your abs and extend your arms out to your sides with palms turned to the floor to help stabilize your body during the exercise.
Lift your hips up off the floor. Do not lift the hips so high that the lower back begins to arch. Continue to press upwards until your body is in a straight line from your heels to your shoulder blades. Extend one leg to the ceiling.
Exhale and gently bend your knee and pull the ball toward your hips. The hips will continue to lift as you pull the ball toward your hips. Keep the torso stable.
Inhale and slowly press the ball away from your hips until the knee is straight, stabilizing with the core, hamstrings, glutes, and arms. Repeat and change legs.