If you’ve been training in the gym long enough, you’ve probably had knee pain when squatting. Squats are a phenomenal exercise that builds lower body strength and is a staple in many gym programs. They challenge your knees and quads, sometimes making your knees cranky. Knee pain when squatting is common, but it doesn’t have to be scary. In this blog, we’ll help you understand why it happens, how to reduce stress on your knees when squatting, and how to improve your squat mechanics in the long term. Let’s dive in.

What Happens To Your Knees When You Squat?

Squatting is one of the most common exercises in lower body training programs; there is a good reason for this. It is an excellent way to train your entire lower body, especially your quads and knees. Squatting is a fundamental human movement.

When we do it in the gym, we usually hold weight on or near the shoulders or in the hands. A lot happens in the squat, but it is typically considered a “knee-dominant” movement. This is simply because of the mechanics of the squat. It requires you to stay relatively upright and bend the knees quite a bit. This means the knees are the primary driver of the movement. Other areas like the hips and glutes contribute, but knees and quads are the focus in most cases.

The degree to which the knees are stressed depends on the specific squat variation you are doing and your individual body mechanics (length of legs vs. trunk, etc.).

Check out the pictures below for a basic demonstration of this. The image on the left is a front squat, and the image on the right is a back squat.

On the left, the weight is held in front of the body, so the torso has to stay much more upright to keep the weight centered over the feet. This means the knees need to come forward and bend more, which usually translates to athletes feeling more stress on the knees and quads.

On the right, the weight is on the back, so the torso leans farther forward to keep the weight centered. This requires less knee bend and quad contribution to the movement.

I have long legs, so the difference isn’t huge, but the comparison still illustrates the point.

All things being equal, the front squat will cause more knee and quad stress than the back squat. If your knees feel good and you’re trying to target your quads, this can be precisely what you want. But if your knees are cranky, a back squat could allow you to train without as much discomfort.

To simplify this, we use the concept of “shin verticality.” Shin verticality refers to how vertical your shin is relative to the floor. The more angled (less vertical) your shin is, the more stress your knees experience. If you look at the pictures above again, you can see that the back squat has a more vertical shin, thus leading to less overall knee stress.

Knees Over Toes Is Not Bad, But It Is Challenging

Many people used to (and still do) think the “knees over toes” position in the front squat picture above is bad for your knees. This is an oversimplification and not true.

The knees-over-toes position might be more challenging for your knees, but that doesn’t make it bad. Knees-over-toes is a position humans need to be comfortable in for activities like squatting, going down stairs, walking downhill, and more.

However, if you’ve avoided this position in your life and training (whether on purpose or not), then do a bunch of squatting, lunging and challenging knee exercises, your knees can get cranky. So, it’s essential to understand where to start and how to train correctly.

If you were prescribed a medication, took 3x the recommended dose, and had side effects, you shouldn’t automatically assume the medication is harmful. You simply misused it. The same principle holds for training.

How To Reduce Stress On The Knees When Squatting

If you’re reading this article, it’s probably because your knees hurt when you squat. We want to give you some tools to work around this so you can keep training. Then, we’ll dive into how to improve your tolerance for the knees-over-toes position.

In a nutshell, here’s how you can reduce knee stress when training:

• Keep shins more vertical

• Do more hip-dominant movements

• Ensure your foot position and mechanics are correct

How Vertical Shins Can Help You Squat

As we discussed above, a more vertical shin when squatting (or doing any other lower body exercise) can help relieve stress on your knees while still allowing you to train your quads effectively. Here are some ways to do this in terms of knee/quad training:

• Squat to a box. This keeps your weight back and gives you a stopping point, which means more vertical shins. See the picture below for an example.

• Leg press instead of squat. This allows you to adjust your foot position without worrying about maintaining your balance.

• Single-leg and accessory work. Exercises like reverse lunges allow you to adjust the movement's mechanics to avoid letting your knees drift forward.

If Your Knees Hurt, Train Your Hips

Stronger hips generally mean happier knees, so training your hips is always a good idea. In the case of cranky knees, this can also allow you to keep training your lower body while taking stress off your knees.

Here are a few ways to do this:

• Back squat instead of front squat. The increased torso lean means your hips need to get more involved. This also ties into the “shin verticality” concept.

• Do more single-leg work. Similar to the point above, single-leg work can be more adjustable, and you can learn to shift stress to your hips when appropriate. If you lean farther forward during exercises like lunges, your hips will be more active.

• Do more deadlifts, hip thrusts, and isolated hip work. This will give your knees a break while they recover and can help improve your foundational strength.

Foot Mechanics When Squatting

You’ll also want to be aware of your feet when you squat. Your knees can suffer if your foundation (feet) are out of whack when you squat.

Here are a few points to keep in mind:

• Keep your feet flat on the floor. This one should be obvious, but you won’t be stable if both feet aren’t firmly on the floor. We teach a concept called “tripod foot” to help with this. When squatting, keep the base of your big toe, little toe, and heel all connected to the floor.

• Keep your weight evenly distributed, side to side and front to back. Be sure you aren’t shifting to one side or putting too much weight on your toes.

• Make sure your toes aren’t turned too far out. A typical squat stance has a slight toe out, but if this gets too exaggerated, it can put weird stress on your knees. If you have trouble with this, it may be due to an ankle mobility issue (keep reading).

How To Make Your Knees More Resilient

We’ve talked about how to train around knee pain and reduce stress on your knees while squatting, but that doesn’t solve the problem. If you want to feel and perform your best, you need to feel confident in your knees. So, how can you make your knees more resilient?

Ankle Mobility for Knee Health

To be more comfortable in a knee-over-toes and/or knee-dominant position, your ankles have to move really well. When your knees come out over your toes, that position is called dorsi flexion. You need this important mobility to have good foot mechanics and lower body stability. This tends to lead to increased loading of the knee.

Here is a video of an ankle mobility drill I use all the time with my patients:

As you can see, this position is key if you want to squat deep and squat well.

How To Improve Quad and Knee Strength

Once you can reliably get into a knees-over-toes position, the next step is to ensure your knee can tolerate it. As discussed above, this position isn’t bad for your knees, but it is challenging. I’ve seen many patients get into trouble by diving headfirst into a challenging knee training program only to stop within a couple of weeks because their knees hurt.

The dose is what makes the poison vs. the cure.

To improve your tolerance to squatting over time, you simply need to start slow and gradually ramp up your knee-dominant squatting.

Let’s go through an example using some of the strategies above. Assuming someone is just starting with this kind of training (or coming off an injury), here is what they could do:

• Leg press through a controlled range of motion for 1-2 weeks

• Box squat for 1-2 weeks

• Gradually lower the box for another 1-2 weeks

• Back squats for 1-2 weeks

• Front squats for 1-2 weeks

In this example, we start with more straightforward, controlled movements requiring less ankle dorsiflexion (more vertical shin) and gradually progress. You could use many different exercises and progressions to improve squat tolerance; this is just one example.

How To Improve Foot Position When Squatting

Building your foundation is always a good idea. When it comes to squatting, this means improving your foot mechanics and stability. Below are some general tips on building better foot mechanics and stability.

• Spend some time barefoot and be aware of the shoes you wear. Do your warm-up barefoot, walk around at home without shoes on (or outside), and let your puppies breathe. Try some minimalist shoes, or at least make sure the shoes you wear regularly aren’t working against you.

• Make sure your toes move well. Here is an article I wrote a while back about taking care of your feet.

• Work on your balance. There are tons of ways to do this: simply stand on one foot, do yoga, do single-leg training, or use special tools (I just got a Slackblock, and it’s really fun).

In general, strength and mobility will improve if you allow your feet to function naturally and put a little time into training balance.

Accessory Training For Knees and Quads

Giving your body some variety in training will also go a long way in improving your knee health and squat performance. I generally like to have people do single-leg training, and occasionally some decline training. Below are some ideas for working these kinds of exercises into your training.

Single-leg work integrates many of the things we have discussed so far. It requires more hip strength, balance, and coordination and generally gives your body some variety in training. Also, we’ve talked a lot about quad training, but don’t forget about hamstrings and glutes. We want to have a good balance of front-to-back strength in the lower body.

Single leg accessory movements to improve your knee health:

• Single leg press

• Single leg squat

• Rear foot elevated split squat

• Lateral step down

• Kickstand deadlift

• Single leg bridge

Decline training is another way to up the ante on your quad and knee work. Anyone who has ever hiked down a steep incline or gone up and down a bunch of stairs can tell you this kind of training really targets your quads.

Decline training ideas for knee health:

• Slant board squats or step downs

• Forward step downs

• Backward walking/sled drags

Squatting Isn’t Bad For Your Knees, Just Train Smart

Hopefully, by now I’ve convinced you that squatting isn’t bad. I also hope I’ve helped you understand how to keep your knees healthy and strong.

Our general approach to treatment is to keep people moving as much as possible. We won’t tell you to stop doing something without a good reason—that’s lazy and uninspired.

We’ll help you understand what's going on, what to do about it, and how to be more resilient so you can live your life to the fullest. We’ve worked with hundreds of people in Lakeville, MA, and the surrounding areas for all kinds of orthopedic issues. If you need help with knee pain or anything else holding you back, call us.