Chances are pretty good that your leg day workout features lunges, squats, and perhaps even some leg presses. However, it’s unlikely that the clamshell exercise is part of your lower-body workout routine… yet!

A long-time favorite of physical therapists, the clamshell exercise is a great (albeit funny-sounding) way to strengthen some of your most crucial leg, hip, and pelvic muscles. This simple low-impact exercise is a good option for anyone looking to improve their muscular strength and stability.

But, what is the clamshell exercise, and what exactly are its benefits? Coming up, we’ll discuss some of the advantages of the clamshell and how you can use it in your training sessions.

What Is The Clamshell Exercise?

The clamshell exercise is a way to strengthen your glutes, hips, and pelvic muscles. The movement is often also used to help people strengthen their core and lower back muscles. In fact, the clamshell exercise’s target muscle is the gluteus medius.

Never heard of the gluteus medius? Well, you’re not alone.

But, you’ve probably heard of the gluteus maximus, which is the large muscle in your butt that’s responsible for your ability to extend your hip and thigh. The gluteus medius, on the other hand, is a much smaller muscle that’s located directly under the gluteus maximus along the back of your pelvis.

While the gluteus maximus is responsible for extending your hip and thigh, the gluteus medius allows you to rotate your hip outward in a process called “abduction.” The clamshell exercise specifically targets the gluteus medius by having you rotate your hip outward to build up strength in that muscle.

What Are The Clamshell Exercise Benefits?

Physical therapists commonly prescribe the clamshell for people with weak hips or anyone with knee pain. This exercise has several benefits, including:

  • Strengthening the gluteus medius and gluteus maximus muscles
  • Increasing hip stability
  • Decreasing lower back pain and tension
  • Preventing injuries in the lower body
  • Strengthening the core and the muscles in the lower back
  • Activating the glutes before squats, deadlifts, or other heavy lifts
  • Increasing muscle definition in the lower body

How To Perform The Clamshell Exercise

To perform the clamshell exercise, you do the following:

  1. Grab a yoga mat and find a flat place to lie down.
  2. Lie down on your side and bend your knees. Be sure that your heels, hips, shoulders, and neck are all in alignment.
  3. Keep your heels together and slowly lift your top leg about 3-4 inches (7.6-10.2cm), while ensuring that your lower leg stays on the floor. Be sure that your hips do not rotate.
  4. Repeat 10-15 times and then switch sides.

Things To Avoid When Performing The Clamshell Exercise

As you can see, the clamshell is a fairly simple exercise. It requires surprisingly little movement to produce results. Despite being so simple, it’s often performed incorrectly. Here are some things that you should not do when performing the clamshell exercise:

  • Don’t Allow Your Hips To Rotate. As we’ve mentioned, your hips should not rotate at all when you’re performing the clamshell exercise. If your hips are rotating, then you’re probably lifting your leg too far. An excellent way to see if you’re accidentally rotating your pelvis is to place your hand on your hip. If you’re doing the exercise correctly, your hand should not move as you lift your leg.
  • Avoid Doing More than 10-15 Reps. If you need to do 20-50 reps to feel fatigued with the clamshell, then you’re probably not going to build much strength with the exercise. In these situations, you should try the clamshell exercise with a band around your knees. This added resistance should make it so that you can only do 10-15 reps before your muscles fatigue.
  • Don’t Let Your Core Slack Off. Your core should be engaged throughout the exercise. This helps to keep your spine in alignment and strengthen your abdominal muscles.
  • Avoid Straining Your Neck. Keep your neck in neutral alignment throughout the exercise so you don’t strain it. Try to rest your head on your arm and remain in one position throughout the exercise.

What Is The Reverse Clamshell Exercise?

If you’re looking for another exercise that can help you develop some of the smaller muscles in your hips, you can try the reverse clamshell exercise. As the name suggests, the “reverse clamshell” is pretty much the opposite of the standard clamshell as it involves lifting your foot, not your knee.

What Are The Reverse Clamshell Exercise Benefits?

While the clamshell exercise benefits the hip abductors (the gluteus minimus and gluteus maximus), the reverse clamshell works on hip adduction, which is the inward rotation of the hips. This movement involves the following:

  • Tensor fasciae latae (TFL) of the outer hip
  • Pectineus of the front upper thigh
  • Small parts of the luteus medius and gluteus minimus of the upper butt
  • Adductor longus, adductor brevis, and adductor magnus muscles of the inner thigh

If you have issues with internal hip rotation (aka adduction), you can have problems with your gait. Many people with adduction problems have knees that cave inward as they walk, which can increase their risk of injury.

Reverse clamshells are one of the many exercises that can help people strengthen these muscles. Reverse clamshells are also used to help relieve hip and back pain, particularly in physical therapy patients.

How To Perform The Reverse Clamshell Exercise

Like the regular clamshell, the reverse clamshell is reasonably straightforward. Here’s what you need to do:

  1. Grab a yoga mat and find a flat place to lie down.
  2. Lie down on your side with your knees bent. Be sure that your neck, shoulders, hips, and knees are in alignment but that your feet are behind you. Your knees should be within a few inches of each other but should not touch.
  3. Rest your head on your arm to keep your neck in alignment and put your other hand on your hip.
  4. Lift your upper foot off of the ground in a slow and controlled manner. Your knees should maintain their distance from each other throughout the exercise.
  5. Repeat 10-15 times until fatigue and then switch sides.

Things To Avoid When Performing The Reverse Clamshell Exercise

The Reverse Clamshell Exercise is again quite simple. But, people often make some small mistakes while performing the exercise that limits its overall effectiveness. So, here are some things to avoid doing when performing the reverse clamshell:

  • Don’t Rotate Your Pelvis Forward. Your pelvis should not rotate forward during the exercise. It should stay in alignment with your shoulders and neck at all times. If your upper knee starts to move forward as you lift your foot, you’re probably rotating your pelvis.
  • Avoid Arching Your Back. Try to keep your core strong throughout the exercise to prevent your back from arching.
  • Try Not To Do Too Many Reps. If you find that you’re not fatigued after 10-15 reps, try wrapping a resistance band around your feet. You should only be able to do a dozen reps or so before your muscles tire out.

Should You Do The Clamshell Exercise?

The clamshell exercise is a great way to strengthen your hip abductors, while the reverse clamshell is excellent for working those hip abductors. Both exercises can help relieve pain, prevent injuries, and improve your athletic performance.

With the aforementioned in mind, the most important thing with any exercise is that you do it properly. When performing either clamshell exercise, be sure that you are slow and methodical with your movements and that you maintain proper spinal alignment. Otherwise, you might not get all the benefits that these movements have to offer.