Why Squats Are Good For Your Knees

Earlier in the week, I was doing some online professional development (doom scrolling through Instagram Reels) and stumbled across a video where a S&C coach was talking about, how once there is damage to the articular cartilage in your knee, deep squats will continue to shred that cartilage until there is nothing left.

“Like rubbing the eraser on the back of your pencil down to the metal.”

Which is wildly inaccurate.

Even worse were the comments, where there was more fear-mongering about deep squats and damaged knees and hips.

Which is a shame for 2 reasons:

One, because the rest of his posts were actually pretty good. Seems like he trains some fairly high level athletes and is a handy S&C coach.

Two, telling someone that may already have knee pain that deep knee flexion is going to rip their articular cartilage apart and make their pain worse, will make their pain worse. And make them terrified of bending their knees. Let alone the fact that there are such a large number of factors that tie into ongoing pain outside of biological ones.

Anatomy of the knee

Deep Breath, Calm Down and Explain.

First off, what we are talking about is knee osteoarthritis (AKA Knee OA or just KOA). Knee OA has traditionally been called a degenerative disease that results from wear and tear on the articular cartilage of the knee joint.

Exercise is recommended as both a prevention and treatment for knee OA, regardless of age, pain, or disease severity (RACGP, 2017).

The specifics of exactly what exercises must be done will depend from person to person. At a base level though, the program should be designed to strengthen all the surrounding musculature of the knee (quadriceps, hamstrings, adductors, calves).

The stronger these muscles and the other soft tissues are around your knee, the more the joint can tolerate, and the less pain you are likely to experience (Jenkinson et al, 2009; Vincent & Vincent, 2012, Mo et al, 2023).

Ok, so exercise is safe, but are deep squats safe?

Yes.

And this line from Jaramillo et al (2024) summarises it perfectly:

“Despite the lack of clear scientific evidence on this association between greater squat depth and increase risk or incidence of injury, it is common to hear in training jargon that the deep squat is harmful to the knee joint.”

In fact, during their review, they found that the inclusion of deep squats may allow for greater physical performance gains.

So, no, deep squats are perfectly safe for your knees and might be better at improving your physical capacities when compared to half or quarter range squats.

Do I just squat through the pain then?

This is where some nuance is required.

Let’s say Bob has come into the clinic after being recommended by his GP. During the consult Bob tells you that he experiences knee pain when walking downstairs and that his doctor told him he had “bone-on-bone” in his knees.

Forcing Bob into a full depth, ass-to-grass squat is probably a bad idea.

One, Bob will likely want to punch you after making him do that, cause it hurt. (and you deserve it)

Two, Bob won’t be seeing you again, which means he will miss out on the treatment that will help his knees - strength training.

If you are smart, you will build Bob’s leg strength, confidence in his capacities and trust in you, to improve his squat depth over time.

But it is important to be able to get into deep knee flexion. You don’t want to live in fear that if you bend your knees too much they’ll explode and you won’t be able to walk anymore.

Deep squats are a simple, easy and safe method to build your joint capacity and tolerance.

Touching Base:

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And let me clarify this as well

This post isn’t really about the guy that I saw saying this on social media. It was a 60 second clip, without full context.

But me reaching a boiling point after seeing too many people spouting the same BS online.

Yes, every case is unique and it is hard to know what the context is when online.

And, it won’t always be necessary or appropriate to make each client I see do a deep squat.

But telling people that deep squats will ruin your knees is just plain wrong, both scientifically and ethically.

Rant over, thank you for reading :)

Jono

For those wanting to do further reading, find the articles listed below:

Impact of the deep squat on articular knee joint structures, friend or enemy? A scoping review. Jaramillo et al, 2024.

Exercise for knee osteoarthritis. RACGP, 2017.

Exercise therapy for knee osteoarthritis: A systematic review and network meta-analysis. Mo et al, 2023.

Knee osteoarthritis. Hsu & Siwiec, 2023.

Resistance exercise for knee osteoarthritis. Vincent & Vincent, 2012.

Effects of dietary intervention and quadriceps strengthening exercises on pain and function in overweight people with knee pain: randomised control trial. Jenkinson et al, 2009.