You’ve heard it from every direction: “Squatting below parallel will damage your knees!”
I’ll get to the point right away— squatting below parallel won’t injure or hurt your knees, but squatting with bad form WILL.
The squat is one of the most difficult and complex exercises to perform and/or teach. There are so many variations in stance, foot position, bar position and depth. Is there a “correct” way to teach or practice those variations? No. Every BODY is different, and that must be taken into consideration when squatting.
Think about injuries, structural genetics (femur length, torso length, hip structure, etc), mobility and lifestyle (desk jobs, etc). All of these affect the squat position and depth in a major way.
Stance
Research indicates that a wider stance (shoulder width or a little greater) with a natural foot position is ideal. What I like to do myself— and when I’m coaching— is stand normal and perform one to two bodyweight jumps, landing in a low squat position. Do it without thinking about your landing stance. From the low squat position, look down and note the width of your stance and at which angle your feet are turned out. That natural stance and foot position is a great place to start in your squats.
There are no “rules” of how wide or narrow your squat should be— nor are there rules for your foot position. You want complete, unrestricted knee movement during squats, and performing them in a stance that is natural to YOU will allow your knees to stay protected.
Knees and Toes
You’ve also heard this on from every direction: “Don’t let your knees go forward beyond your toes!”
Your knees moving close to or slightly past your toes is acceptable and will actually keep your form and muscle activation intact during squats.
Your knees moving too far beyond your toes may cause stress to your knees, so it is something you want to control and practice, but allowing a bit of forward movement will keep you from recruiting your hips and lower back during the squat.
You’ve also heard that squatting below parallel is “bad for your knees.” Keep in mind that the strongest knee force is at and around the 45-degree knee flexion (bent) range. That means that the most knee-shearing part of the squat is above parallel! So, don’t be scared to get low.
Most important is the act of “pushing” your knees out during your squat so that they don’t collapse inward. You don’t have to exaggerate this; just keep it in your brain and push them out just enough to stop them from moving inward. Allowing this inward knee movement during squats is usually where most of the pain and injury in your knees is initiated.
Back
A full squat means getting below parallel with your spine remaining neutral. If you start to get flexion in your lower back, you aren’t ready to squat deep with weight just yet. The goal is to get full depth, entire back and core engaged (rigid extension), lordotic curve of the lower back (lumbar spine) maintained all the way down, and eyes straight ahead or 3-4 inches in front of your feet on the floor.
While squatting below parallel, you find that you lose the lordotic curve of your lower back and your hips “tuck” under— that’s your signal to stop and not squat quite as deep.
Bar Path
The bar needs to be right above the middle of the top of your foot during the entire squat movement. At the very top, make sure the bar, your hips and your mid-foot are in alignment. As you go down into your full squat, the bar path should remain vertical in a straight line going down and back up. At the bottom, the bar should still be aligned with the middle of your foot.
Making Changes
Also, at and around the 45-degree knee flexion (bent) range is the place where your hamstrings have the most muscle activity and contraction. Quads and glutes muscle activity and contraction are at their best and strongest at 90 degrees and below (deeper). So, the ENTIRE squat is great for your legs and glutes!
Keeping the above tips in mind, along with practicing progressive overload (gradual increase in work load over a period of time) will help in reducing injury while practicing the full/deep squat.