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Mistake: Weight Too Far Forward
To take care of your knees and really engage your glutes, keep your weight in your heels. You should be able to freely wiggle your toes as you sit back into your squat. Weighting your heels also keeps the knees from moving beyond your toes, which can seriously strain that joint.
The Fix:
Practice squatting with a stable chair or weight bench behind you, and aim to lower your booty onto the front third of the seat — quietly and with control, no plopping down. This will help you shift your weight far enough back to truly challenge your glutes.

Mistake: Leaning Forward
When squatting, you want to keep your torso fairly upright, but tight hips can pull the upper body forward, straining the knees and the low back. Leaning forward also interferes with your ability to go deep in the squat, decreasing the amount of work for your backside.
The Fix:
Before a strength training session, do a dynamic warmup to open the front of the hips. Walking lunges work well as an active stretch for the tight hip flexors. To keep your torso upright, use an exercise ball at the wall for your squats and single leg squats too. Here are details on how to set yourself up for ball squats at the wall — just make sure you’re going deep enough into the squat so your thighs are parallel to the ground.

Keep on reading for more about squats after the break.

Mistake: Funky Knee Alignment
When squatting, you want your knees to track in line with both your ankles and hips, protecting the joint from unnecessary strain.
The Fix:
No matter if your knees roll in or out, watch your alignment in a mirror and correct it as you bend and straighten your knees. To encourage correct alignment, place a flexible ball between your knees to help keep your joints stacked. If your knees veer toward the mid-line, try a narrower stance; conversely, if your knees stray to the outside, widen your stance, and roll the IT band (here’s how to massage your ITB with a foam roller), the fascia that runs on the outside of the thigh from the hip to the knee. If this soft tissue is tight, it can interfere with correct knee tracking.

Mistake: Not Going Low
Yes! You want your thighs parallel to the floor. If you suffer from tight calves, you will find this hard to do while keeping your heels weighted.
The Fix:
Loosen up your tight calves before your strength training session. Once your body is warm from doing five minutes of cardio, roll your calves with a roller (here are instructions for rolling out your calves), then give them a stretch. After prepping your lower leg, squatting low should feel much easier.

See original article By Susi May here