How to Do the Clam in Pilates

Proper Form, Variations, and Common Mistakes

Verywell / Ben Goldstein

Also Known As: Clamshell, oyster

Targets: Hips, thighs, gluteal muscles

Equipment Needed: Mat

Level: Beginner

The clam is a popular and easy Pilates mat exercise. It is a basic movement that is a good introduction for beginners and provides a foundation for more advanced Pilates exercises. The Pilates clam is very easy to do. Once you get into the rhythm, you will find it to be a great addition to your workout that targets your hips, thighs, and those all-important glutes.


Pilates clam is a simple exercise that begins to tone the hips and thighs. It also teaches pelvic stability as the leg rotates inward and outward at the hip. This exercise is calling on your deep six hip muscles. These smaller and lesser-known hip muscles help with the movement of your legs and hip, create pelvic movement and are important to the overall health and integrity of your hip.

Clam will help you build the strength and flexibility you need in more difficult side-lying exercises. You will need the same skills—pelvic stability, shoulder stability, abdominal control, and moving the leg independent of the pelvis—when you move on to exercises like the side kick series.

The clam is often prescribed in physical therapy for people who have knee pain as it activates the muscles needed to support good knee function. It is also used in rehabilitation after total hip replacement and hip fracture.

Step-by-Step Instructions

You will need a Pilates mat or a firm, padded surface.

  1. Lie on your side with your hips and shoulders in a straight line.
  2. Bend your knees so that your thighs are at a 90-degree angle to your body.
  3. Rest your head on your top arm as it is stretched out overhead, or bent, whichever is more comfortable. Make sure your neck is long so that your head is not tipped back or tucked forward.
  4. Bend your top arm and place your hand on the floor in front of your chest for extra stability.
  5. Stack your hips directly on top of each other vertically. Do the same with your shoulders. Use your deep abdominal muscles to keep this alignment throughout the exercise.
  6. Inhale and keep your big toes together as you slowly rotate your leg in the hip socket so that the top knee opens. Open the knee only as far as you can go without disturbing the alignment of your hips.
  7. Exhale and slowly bring your knee back to the start position.
  8. Repeat the clam five times, then change sides.

Common Mistakes

Avoid these errors to get the most from the clam.

Rolling Top Hip

Do not roll the top hip forward or backward as you separate your legs.

Too Much Speed

As with any Pilates exercise, you should perform the clam smoothly and with control.

Straining Neck

Your neck should be in neutral position so you don't strain it. Your neck should not move during this exercise.

Modifications and Variations

The clam is the foundation for other Pilates exercises where you will lie on your side. Finding that perfect balance to keep your body aligned is key and it is important to practice the clam as often as you can. When you do find your comfort zone with the clam, you can begin to build on it.

Up for a Challenge?

Begin by adding a breath pattern to your clam routine. Follow your breath and open your knees when you exhale and close them when you inhale. Keep your breath slow and steady and follow this pattern with a gentle rhythm.

The clam and high clam are both beginning Pilates exercises. Once you are familiar with the clam, you will want to move onto the high clam. The difference is not significant and you will find that it is also a great workout for your thighs.

To do the high clam:

  1. Lie on your side with your hips and shoulders in a straight line. Stack your hips and shoulders directly on top of each other vertically.
  2. Place your top hand on the floor in front of your chest.
  3. Bend your knees so that your thighs are a little more open than a 90-degree angle.
  4. Rest your head on your outstretched top arm.
  5. Keep your knees together and down as you lift your feet, together, away from the mat.
  6. The inside edges of your feet stay together as you rotate the top knee open.
  7. Keep your feet up but bring the top knee back down to join the bottom knee.
  8. Repeat the open and close with resistance six times.
  9. Rest and repeat.
  10. Change sides and repeat.

You can add a theraband around your knees to increase the load on the hips for either clam or high clam.

The clam squeeze and reverse clam are similar to the clam. Instead of lifting your knee, you will keep your knees together.

For the clam squeeze:

  1. Lie in the same position as the clam and place a pillow between your knees.
  2. As you slowly exhale, gently squeeze the pillow with your knees.
  3. On your inhale, release the pillow.
  4. Repeat this five times, then change sides.

For the reverse clam:

  1. Lie in the same position as the clam.
  2. Keep your knees together and slowly lift your shin and foot upward (your clam is open to the rear) as you exhale.
  3. On your inhale, slowly lower your shin and foot.
  4. Repeat this five times, then change sides.

Safety and Precautions

This exercise is generally safe for most people to perform. If you have had recent hip or knee surgery or injuries, discuss any exercise with your doctor. You should not feel any pain during the exercise. If you feel any pain, release and do not continue.

Try It Out

Incorporate this move and similar ones into one of these popular workouts:

1 Source
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Princeton University Athletic Medicine. Pelvic stabilization, lateral hip and gluteal strengthening program.

Additional Reading

By Marguerite Ogle MS, RYT
Marguerite Ogle is a freelance writer and experienced natural wellness and life coach, who has been teaching Pilates for more than 35 years.