The squat is a primal movement pattern, making it one of the most functional and fundamental skills that we need to improve strength. It's more than a leg exercise, too; squatting can release large amounts of natural growth hormones, like testosterone and HGH, optimizing muscle development and overall strength gain. However, injuries are nearly inevitable if you back squat with flawed form.
When fine-tuning technique, it should go without saying that your heels remain planted on the ground and that you gun for good depth — thighs at least parallel to the ground. Beyond those basics, you should be aware of the four subtle mistakes below that lifters often make. Avoid them, and you'll ensure that you progress faster, create muscle balance, and avoid injury.
Mistake 1: Bad Head Posture
Good squats require spinal alignment with the chin down to keep the neck in a neutral position. The head should follow the torso: As your chest rotates forward as you lower, you'll begin looking down. Try focusing no higher than your knees in the mirror in front of you at the gym. You may notice that this simple alignment tweak helps you to squat deeper.
Mistake 2: Fearing Butt Wink
Butt wink is a phenomena where mobility restrictions pull on the pelvis, forcing it to tuck your butt under your lower back. (Get a deeper explanation here). You can expect minor butt wink to occur on most people who try to squat deep, and it's not always dangerous. This tuck is only worrisome if the spine is pulled into flexion (rounded). To minimize pelvis tilt and prevent back flexion, find the foot width that promotes your deepest comfortable squat and least tilt under very light loads. Use that width for your workouts. Because the butt wink is a range-of-motion issue, always include hip-mobility moves in your training. Two good ones are split-stance squats with the rear leg elevated and Spiderman walks.
Mistake 3: Treating the Squat as a Leg Exercise
The squat doesn't isolate the lower body. Relying on the legs to get you through a set may work using lighter loads, but it's not going to cut it if you really want to get stronger. Instead, focus on creating total body tension. Start with tightness on the bar. Try to pull the bar apart with your hands by gripping tight and squeezing outwards. That will engage your back muscles and create tension through the entire posterior chain. Next, take a big breath, fill the stomach and lungs with air, and hold that pressure through the bottom range of your squat. Exhale close to the top of the lift (not at the very bottom). Doing this creates the abdominal pressure needed to stabilize the spine and have a much more sturdy lift.
Mistake 4: Ignoring Your Body Type
Conventional wisdom on big, compound movements often comes with cues that disregard the differences in skeletal structure lifters have from one another. The squat is no exception. Tall lifters with longer legs will never break parallel if they stick to the "don't let the knees pass the toes" rule. Likewise, if you've got hip sockets that are toward the front of your body, a narrower shoulder-width stance may work better than a traditional hip-width stance. Alternatively, if you've got wide-set hip sockets, then a wide stance may promote the best quality squat.