Jumping jacks have been a popular exercise in military and fitness circles for many years now.
They’re a great way to get your heart pumping and improve your cardiovascular fitness.
That being said, just like any exercise, they can cause certain issues, such as knee pain.
So, if jumping jacks are wrecking your knees, here’s why and how to fix it.
Jumping jacks will mainly hurt your knees due to incorrect feet positioning. When you land if your feet are pointing straight ahead there is a greater likelihood of your knees collapsing inwards. This can lead to soreness, and eventually a knee injury. Therefore, turn your feet out slightly (approximately 30 degrees) and this will ensure that your knees are in a more stable position.
Where Are Your Feet Pointing During Jumping Jacks?
So, the most obvious reason for knee pain during jumping jacks comes down to what you’re doing with your feet.
In all honesty, I don’t think many people pay much attention to their foot starting position or how they land.
Don’t worry, I get it, jumping jacks force your heart and lungs to work extremely hard, so your attention is probably elsewhere.
Furthermore, jumping jacks also require a great deal of core stabilization in order to protect your spine.
How to Perform “Knee-Friendly” Jumping Jacks
However, by ignoring your feet, especially when you land, can lead to knee pain and even serious injury.
So, you’ll typically start with your feet together, before jumping out and spreading your legs, while your arms go overhead before returning to the starting position.
Sounds simple enough, but you may have already made a mistake.
The vast majority of people I see performing jumping jacks will initially land with both their feet pointing straight ahead.
Granted, your feet definitely start in this position, but this can cause all sorts of problems when you spread your legs and land on your feet.
By keeping your feet pointing straight ahead there is a higher likelihood of your knees collapsing inwards.
This may actually not be that noticeable to you, but with every jump you’re placing undue stress on both knees.
So, when you land in the “legs spread position” ensure both feet are pointing out slightly at approximately a 30-degree angle.
Simply turning your feet out will also activate the glutes, which in turn makes the exercise far more efficient as a fat-burning, cardiovascular exercise.
Plus, you no longer have to worry about your knees falling inwards, which of course can lead to injury.
In the video below you can see this foot positioning executed perfected in the slowed-down version of the jumping jack.
Jumping Jack Alternatives to Avoid Knee Pain
There is one simple alternative to jumping jacks that will definitely save your knees.
However, I will admit that this is a regression, i.e. a much easier version.
That being said, you are still moving your legs and your arms.
Plus, you should be able to perform a much higher volume of “modified jumping jacks” then you usually would with the full version.
So, you’ll definitely be working your cardiovascular system.
This simply involves moving your arms in exactly the same way, but stepping out with one foot at a time.
Here’s exactly how to perform the movement.
How Often Are You Performing Jumping Jacks?
There is a case that your knee pain could be an overuse injury.
This is obviously going to be more likely if you perform jumping jacks on a very regular basis, especially if you’re using a lot of volume.
This is known as patellar tendonitis, often referred to as jumper’s knee.
That being said, this can be caused by any excess of jumping and is actually quite common among runners too.
Jumper’s knee is actually an inflammation of the tendon that connects your kneecap to your shinbone.
Additionally, jumper’s knee can be more prevalent if you’re jumping on hard surfaces.
Your knees will almost act as shock absorbers every single time you jump and your feet land on the ground.
You’ll typically notice that you experience pain and tenderness, and sometimes you may see swelling too.
Additionally, it won’t be just jumping jacks that are causing an issue, as you’ll probably experience pain while walking or running.
Then again, in some severe cases you may feel pain when trying to bend or straighten your leg.
Unfortunately, if this is the case, I urge you to make an appointment with a medical professional to discuss potential tests, remedies and treatments.
Finally, you should obviously not be performing jumping jacks if you have patellar tendonitis.
In fact, you should completely stop exercising until you have spoken to your Doctor or healthcare provider.
Key Learning Points
- Your foot positioning when you land with your legs spread during jumping jacks is probably what is causing your knee pain.
- Don’t land with your feet pointing straight ahead, but rather have your feet turned out approximately to a 30-degree angle.
- You can perform modified jumping jacks, which incorporates the exact same movement pattern for your legs and arms, but without actually jumping.
- Knee pain from any jumping exercises could be a sign of “Jumper’s Knee” (patellar tendonitis)
- Patellar tendonitis commonly occurs from overuse and especially if you regularly “jump” on hard surfaces.
Sticking with the lower body area, discover more about why jumping jacks hurt your calves.
Hi, I’m Partha, owner and founder of My Bodyweight Exercises. I am a Level 3 Personal Trainer and Certified Strength & Conditioning Specialist through the Register of Exercise Professionals, United Kingdom. I have been a regular gym-goer since 2000 and coaching clients since 2012. My aim is to help you achieve your body composition goals.