The biggest mistake you can do on Squats is not going below parallel. Half or Quarter Squats increase risks of knee injuries by creating muscle imbalances. Check this thread in StrongLifts.com Forum for more info.

The 2nd biggest Squat mistake is lowering yourself by moving your knees first. This impairs performance and can also cause knee injuries. The correct way to squat is using your hip muscles. Here’s how.

How NOT to Squat. Here’s a video of reader Banderbe’s Squat technique. Pay attention to the bar placement and his knees/hips movement. He squats down by flexing his knees first instead of his hips, and uses a high bar position.

Why This Is Bad Squat Technique. Low bar Squats emphasize your posterior chain. High bar Squats are quad dominant. It’s not bad to Squat high bar as long as your training program is balanced. But moving your knees first is bad.

• Strength Loss. Power comes from your hips. You can’t use your hip muscles optimally when squatting down by flexing your knees first.
• Knee Injury. Squatting down by flexing the knees first impairs posterior chain strength. A weak posterior chain can cause knee injuries.
• And Much More. Anything becomes possible when you squat low bar by flexing your knees first: excessive leaning forward, lower back rounding, heels off the floor, etc.

How to Squat Correctly. Move your hips first. This stretches your hamstrings on the way down, storing energy in your stretched muscles. Use this energy on the way up by bouncing off your stretched hamstrings.

• Sit Back. Think of sitting on a toilet. Squat down by pushing your hips back as far as you can. This stretches your hamstrings, building tension.
• Lean Forward. Put the bar low on your traps and lean forward. Keep the bar above the center of your feet so you don’t lose balance.
• Look forward. Avoid doing a goodmorning. Look forward while keeping your neck straight. Big chest, shoulder-blades back & down.

Good Squats, Bad Squats. Here’s an example of good vs. bad Squat technique. First 30 seconds is bad technique, next 30sec good technique. Ignore the depth: I’m using a broomstick. Focus on the knees/hips movement.

How to Learn Correct Squat Technique. Most people are quad dominant and have tight hamstrings/adductors. Moving your knees first is usually caused by weak posterior chain muscles or lack of hip mobility. Here’s what you can do

• Squat Stretch. Hold on to something. Chest up. Shoulder-blades back & down. Lower leg close to perpendicular to the floor. Knees out. Push your hips back. You’ll feel tension in your hamstrings/adductors. Hold the stretch. Aim for 30 seconds while trying to break parallel.
• Wall Squats. Force you to move your hips first instead of your knees. Stand against a wall with your hands between your legs and squat down. Push your knees out.
• Practice. Low bar position. Chest up. Shoulder-blades back & down. Curl your toes up. Push your hips back as far as you can. Lean forward. Knees out. Break parallel. Bounce of your hamstrings.

The same principle applies to High Bar Olympic Squats & Front Squats. The upright torso position makes sitting back harder but you still must move your hips first. Dan John recommends to “squat between your legs”.

Best cue is to go for the hamstrings stretch. When you squat down correctly, you’ll feel tension in your hamstrings. The greater the tension, the bigger the force on the way up, and the more weight on the bar.