How to Do The Clamshell Exercise With Perfect Form
Here's a step-by-step guide for how to do the clamshell exercise. Try this simple exercise for strengthening the hips and protecting your knees. Plus, discover what muscle groups they work. And the #1 mistake to avoid while doing them.
In the 1920s, the gray wolf population in Yellowstone nearly vanished.
Early park managers viewed them as causing “wanton destruction” to livestock, deer and elk. To protect these “desirable” animals they nearly exterminated the gray wolves from the area. And sure enough, over the next 70 years, elk herds grew larger and larger.
But with that these elk herds started overgrazing the land which caused willow and aspen trees to dwindle. This caused the songbird population to take a nosedive. Fewer trees also meant beavers lost their food source and primary building material for their dams. With less dams, the streams started eroding and they became deeper but less wide, which made it even harder for willow trees to flourish. Eventually, the gray wolves were reintroduced to the area, and finally after 25 years parts of the ecosystem are starting to heal.
Just like the gray wolves were wrongly blamed for problems in the ecosystem, the same goes for certain joints in the body.
The knee is one of them.
Over the years, people have asked me countless times how to strengthen the knee or how to stabilize the knee.
The problem is they are going after the wrong suspect.
They assume that because the knee is frequently injured, that something is wrong with it. But the symptom of the pain is usually not the source of the pain.
There are exceptions to this. For example, if you’re blind-sided by a linebacker, chances are your knee can’t hold up this force. But outside of these collision injuries, we can prevent many types of knee injuries. And in many cases, the hips are the true culprit.
If the hips are functioning correctly, the knee tends to stay healthy. If the hips are functioning correctly, the back tends to stay healthy as well. And one of the best ways to keep the hips functioning is with something called the clamshell exercise.
So What Is The Clamshell Exercise?
Clamshells are a side-lying exercise for strengthening muscles in the hip. It’s a deceiving little exercise that doesn’t look like much but it’s doing quite a bit including:
Strengthens your Glutes When you do clamshells you’re activating your glutes (which are your butt muscles). These are important for walking, running, climbing stairs, picking up objects from the ground or even standing up. When these muscles are not activating correctly, the lower back tends to compensate. When it comes to the clamshell exercise, it works not just the largest glute muscle (glute maximus) but also a smaller one called the glute medius.
Knee Stability In seminars I’ve had audiences stand up and put one hand on their glute. Then gently move their knee side to side. When you do this you should feel muscles in your hip activating. That’s because muscles like the glute medius actually help stabilize your knee. Like I mentioned before, many people want to point their finger at their knee not being strong enough, but in many cases it’s the hips (and glute medius) that aren’t strong enough to control the knee.
Hip Health Muscles along the outside of the leg (such as TFL-IT Band) tend to get stiff. If you’ve ever had a massage or foam rolled this area, you know what I mean. When this area gets stiff it can actually rotate the hips and cause your femur not to move correctly in the hip socket. This can cause hip pain and restrictions in movement.
However, when you strengthen the glute medius, this helps guide your femur so it moves smoothly in the hip socket. And clamshells do exactly that.
Set-Up: Start in a side-lying position with your legs stacked on top of one another and your knees bent at about a 45 degree angle.
Movement: Keeping your feet together, you’re going to open your knees without rotating at the spine. Then return to the starting position. You should feel this exercise working the glute muscles. Do 10-15 repetitions each side.
Common Mistake with Clamshells
Rotating The Spine: This is the most common mistake. You want to make sure that only your leg is moving. Your hip should not move either. Sometimes it helps to have your hand on your hip to monitor this. Once again you should feel this exercise working the glutes.
What If I Can’t Activate My Glutes?
In some cases it’s because these muscles have not been used in a while and are extremely weak. In other cases, it’s because your alignment is off which makes these muscles harder to activate. Here are a few tips to help:
Tip #1: Hand on the glutes Place your hand on your glute when you do the exercise. Believe it or not, when you touch a muscle, it helps it activate.
Tip #2: Bring the legs back Another tip is instead of bending your legs forward at a 45 degree angle, you would bring them backwards. Meaning: You would do the clamshell with your upper legs in-line with your torso.
Tip #3: Pillow underneath you Another way that’s worked for some of my clients is to have a pillow underneath them (right above the hips). This can help put the spine in better alignment – especially for those with larger pelvic bones.
How to Make Clamshells More Challenging
After you get the hang of clamshells, here's a little variation that you can try out. In this video by Mike Reinold - you'll see the band resisted clamshell.
This is a great way to work the glutes even more. Just make sure you don't rotate from the spine (or the hip). All the motion shoulder come from the leg.
When Should I Do Clamshells in My Work Out?
Clamshells are a great exercise for the beginning of a warm-up. Do 10-12 repetitions on each side. This is going to activate the glutes and other important hip muscles. That way you are more likely to use them during the rest of your workout.
Meaning: your activated glutes are going to help you when you do squats, lunges, step ups or other leg exercises. And ultimately that's going to allow you to get more out of those exercises.
It’s easy to overlook such a simple exercise like the clamshell.
However, it will improve not just how well you function but also the rest of your workout. Try them out and see for yourself.