Your hamstrings, a group of three muscles in the back of your thigh, work to bend your knee and extend your leg at the hip. Isolating these muscles without specialized gym equipment is difficult. If you don't want to invest in an actual home gym, stability ball leg curls are among the most challenging -- and thus most beneficial -- options available for working your hamstrings.
Choosing a Ball
In general, when you sit on the correct-size stability ball your hips and knees will bend at a 90-degree angle. The ball should also compress about six inches beneath your weight. If you struggle to maintain your balance on the ball, letting a little air out of the ball makes managing it easier until your core strength and stability improve.
Muscles Worked
Your hamstrings are the primary movers during stability ball leg curls. But the stability ball forces your entire body to work against the ball's tendency to roll readily in any direction. As a result your rectus abdominus, obliques, glutes and erector spinae are constantly active during leg curls. Your gastrocnemius also crosses the knee, so it activates to aid the hamstrings as well. Note that although your arms spread on the floor do provide a wider base for stability, you should never feel the strain of this exercise in your shoulders or arms. Your abdominal, hip and back muscles should do all the work of stabilizing.
Glute Bridge
The stability ball leg curl is actually two exercises in one. You must maintain a stability ball glute bridge during, before and after each leg curl repetition. During the bridge your heels should rest on the peak of the stability ball, and your body should be straight from feet to shoulders, which rest on the floor. Spread both arms at a roughly 45-degree angle to your body for extra stability. Ideally, you should be able to perform a solid glute bridge for about 45 seconds before performing stability ball leg curls.
Modifications
Once you can safely hold a glute bridge with good form, bending both knees forces your body into a leg curl. Your body should stay as straight as possible from shoulders to knees as you bend your knees, rolling the ball toward you, then straighten your legs back into the glute bridge position. Once you can perform 12 to 15 repetitions with good form, work your way up to more difficult variations. Options include shifting your hands in closer to your body to make balancing more difficult, or performing the curls with just one leg at a time. Extend the other leg straight, in line with your body, and remember to do an equal number of repetitions on each leg.
Member Comments