The clamshell is one of those exercises that seems a little too easy at first glance. After all, you’re just lying on your side and moving your knee up and down casually. And yet, when you do a clam exercise with good form, it actually contains the benefits (and the burn).
The clam, or clamshell, is a side lying exercise that targets the hips, buttocksand thigh musclessaid Judith HouwaardPilates instructor and owner of Amavi Movement. “It got this name because of the similarities to a clam opening and closing,” she told Bustle. (Sounds cute…until you make a lot of it.)
Clams are great for improve the strength, mobility and stability of your hips, says Houwaard. This is because the opening and closing motion targets the external rotation of your upper hip as it moves your leg bone into the hip socket, she explains. Add clams to your routine often enough, and it can really start to strengthen this area and make you feel more mobile.
Since this exercise focuses on strengthening one side of the body at a time, you end up correcting any muscle imbalances you may have in your hips, adds Houwaard, which can decrease body discomfort and reduce your risk of injury to be misaligned.
As a bonus? This movement is also a great way to strengthen the middle of the glutes, which in turn reduces stress and tension in the lower back, says Houwaard. “The gentle activation of the core muscles also helps with that,” she says. Ready to try this simple but effective exercise? Here’s how to do it right as well as how to modify it.
How to do the clam exercise
– Lie on a mat on your side with your hips aligned with your shoulders.
– Bend your knees and bring your legs up to a 70-45 degree angle to your body.
– Place your head on your arm or support it with a small pillow or towel.
– Make sure your head is not forward or backward from the cervical spine.
– Put your hand on the floor in front of your chest for more stability, or place your hand on your hip to make it harder.
– Make sure your hips are stacked and don’t let your torso collapse to the floor.
– Engage your deep abdominal muscles, aka the transverse abs, to maintain alignment during the movement.
– Inhale to prepare. On the exhale, keep your toes together as you rotate the hip joint and open the knees. Think of directing the movement with your upper knee, like opening a clam shell.
– Rotate your top knee open but only as far as you can without losing your hip alignment.
– Return to the inspiration and repeat.
– Do 10 to 12 repetitions, then repeat on the other side.
How to modify the clam
To make this move a little more challenging, Thomas recommends adding a resistance band to your quads to create more tension as you raise and lower your knees. For even more burn, add another resistance band around your ankles.
Do you have an exercise ball handy? “Another great way to shake it up is to add a small exercise ball between your knees or a pillow and press it into the lower part of the movement,” Thomas told Bustle. “This results in the activation of the muscles in our inner thighs.”
Common mistakes to avoid
As with any exercise, it’s important to pay attention to your form at all times in order to get the most out of the movement. Thomas cautions against letting your torso tip forward as you raise and lower your top leg.
“To avoid this, focus on maintaining the same distance between your ribs and your hip bones,” she says. “You can do this by placing your thumb on your lower rib and your middle finger on your hip bones to assess any changes.”
You also don’t want your hips rolling forward. Keep your hips, knees, and feet stacked. And last but not least, remember to go slow. “Watch your speed,” says Thomas. “You don’t want to see any body sway. You want to use muscle control, not momentum.
McBeth, JM. (2012.) Hip muscle activity during 3 side-lying hip strengthening exercises in long-distance runners. Train J Athl. doi: 10.4085/1062-6050-47.1.15.
Sidorkewicz, N. (2014.) Review of the effects of changing hip orientation on gluteus medius and tensor fascia latae interaction in common non-weight-bearing hip rehabilitation exercises. Clin Biomech (Bristol, Avon). doi: 10.1016/j.clinbiomech.2014.09.002.
Willcox, E. (2013). The influence of variation in hip angle and pelvic position on muscle recruitment patterns of the hip abductor muscles during clam exercise. https://www.jospt.org/doi/10.2519/jospt.2013.4004