Why Deep Squats Are Actually Good For You

So we’ve all been told that the “right” way to squat is toes pointing forward, lowering the hips to no deeper than knee level and strictly keeping the knees behind the toes, awkwardly leaning forward as we feel we are going to lose our balance backwards.  This is kind of weird considering how we have to move to get down on the floor, to pick something up from the floor, to poop on the ground (in previous generations or now for some of us), or how people sit and hang out in places where chairs aren’t common.  I won’t go into how this weird idea of a squat got introduced to the popular mind but I do want to go over some aspects of the deep squat, why it’s good and how it can benefit us.

The Actual Correct Way to Squat

Ok I just couldn’t resist this amazing image of what the human body can do. I would have to say this is definitely this yogi’s correct squat technique. Continue on below to learn more about correct squat technique for the average human body.

According to authors Comfort, McMahon, and Suchomel in “Optimizing Squat Technique- Revisited,McMahon”, based on a thorough review of scientific evidence “a full depth squat, with a natural foot position, approximately shoulder-width apart, with unrestricted anterior movement of the knees, an upright trunk, with a forward and upward gaze is recommended.”

Boom! So that’s it, but read on if you’d like to know a little bit more about why.

Forces on the Knee

Forces on the knee are higher when you squat lower, right?  No, actually the highest levels of stress on the knee are seen at around a 90 degree knee angle which corresponds to a squat to parallel. It turns out that as we allow the knees to bend and hips to sink below parallel in the squat, the anatomy of the knee allows enhanced load distribution and enhanced force transfer with lower compression under the knee cap.  Our knees were actually built for deep squatting.  Go figure. So when we squat to parallel, we are actually stopping our momentum and restarting in the zone of highest forces.  Bad. So go lower and turn the movement around when the forces are lower. Good.

Load Concerns

The whole point of squatting is to increase strength, right? That means using a heavy enough weight that our muscles get fatigued which will cause positive adaptations. Doing a deep squat fatigues our muscles faster with a lighter load than doing a half or quarter squat. This means that we can use a lighter weight to stimulate strength adaptation. A lighter weight means less compression on our spines, hips, and knees.  Good.

Keep the Knees Behind the Toes or Your Knees Will Explode

A common myth of squatting is that we must at all costs keep the knees behind the toes.  Funny how this doesn’t feel natural at all but we have decided this is the “right” way. This awkward squat actually increases stress at the hips and spine. When we do a squat to parallel and force the knees to stay behind the toes, we have to lean our chest  forward in order to avoid losing our balance backward. When we do this with a weight at the shoulders, this causes increased “anterior shear” forces at the lumbar spine.  

An anterior shear force in the lumbar spine is a force that could cause a vertebra to slide forward on top of another vertebra if not held strongly enough by the spinal joints, ligaments and muscles.  The lumbar spine is not as resistant to shear forces as other forces. These forces can cause failure of the stabilizing joints of the spine, possibly leading to spondylolisthesis- the slipping of one vertebra forward on another.  However, I don’t want to introduce a lot of fear here about anterior shear forces. Please keep in mind, when we progress weights at the right speed and with the right form, the spine itself as well as the muscles around it, will gradually become stronger and more resistant to all forces.   

Real Life Examples in Weightlifters

You may assume that weightlifters who are consistently squatting with massive amounts of weight would have high rates of injury because of all the forces they are putting on their knees, right?  And they probably have a ton of arthritis and joint degeneration over the years, right? Actually, NO they don’t! Turns out that the body is not an inanimate machine that just wears out as you use it.  No, the body actually gets stronger and tougher as you use it. Think about it- if you were to start doing a lot of shoveling without gloves, would the skin on your hands simply wear away to the bone, or would your skin thicken up into a callus?  Case in point, the knee joints of weightlifters were found to have thicker cartilage than the knees of untrained individuals. Thicker cartilage shows increased stiffness that corresponds to increased tolerance to mechanical stress.

What about injuries?  One study found Olympic weightlifters had 3.3 injuries per 1000 training hours over a 6-year period.  Another study found that Olympic weightlifters had a lower prevalence of injury than US basketball players, US track-and-field athletes, American football players and US gymnasts.  The point here is that yes athletes do get injured, but weightlifting has inaccurate bad rep as being particularly dangerous or injurious. I would also propose that when people perform correctly instructed weightlifting as part of a fitness routine, this injury risk will be even lower because we are not pushing for maximum weights at any cost.  Fitness participants are generally just trying to be healthy, and don’t have to push the body to the absolute limit.

Benefits of Deep Squats

Decreased injury risk:  Squatting past parallel increases the challenge to the gluteus complex and hamstrings.  This helps avoid dominance of the quadriceps muscles during sport and life activities. Quad dominance is thought to increase injury risk so it’s something to avoid.  Deep squatting may also strengthen structures of the knee, again protecting against injury.  

Stay independent longer: We need the ability to squat to get up and down from the floor, get off the toilet and pick things up from the ground.  Training the deep squat will help us to stay independent longer as we age. This is why older adults especially should be practicing the deep squat under as much load as they are safely able.  

Improved performance:  Studies show deep squat training increases vertical jump moreso than half and quarter squat training.

Look good in your jeans:  So if we are working the gluteus complex more in a deep squat, we are going to be building that highly sought after booty.  Honestly I wish that wasn’t even a thing that people cared about. But if it gets people into fitness, and then they get the side benefits of feeling better and being happier, then I’m all for it.  

Learning to Squat Correctly

Technique is important. If you’re not sure if you’re squatting correctly, head to a physical therapist to learn. In fact, come see me specifically. I love teaching people how to squat. As a physical therapist, I can assess what’s holding you back from doing the perfect deep squat and work with you to fix it.


Hartmann H, Wirth K, Klusemann M. Analysis of the Load on the Knee Joint and Vertebral Column with Changes in Squatting Depth and Weight Load.  Sports Med  2013 Oct;43(10):993-1008. 

Fry A, Smith JC, Schilling BK.  Effect of Knee Position on Hip and Knee Torques During the Barbell Squat. Journal of Strength and Conditioning Research, 2003, 17(4), 629–633.

Comfort P, McMahon JJ, Suchomel TJ. Optimizing Squat Technique—Revisited. Strength and Conditioning Journal.  2018 Dec; 40(6), 68-74.