I get this a lot with new sign ups who tell me they can’t squat because they have bad knees. In the vast majority of cases the squat is not the problem. For some it’s the lack of squatting that has caused weakness and left the knees with no resistance to injury. For nearly all it’s poor form that’s the real issue. The main issues I see are :
Not squatting deep enough -Partial range of motion squats, seen in most boot camps, aerobics classes and also the weights section of your high street gym has a number of problems. The main one being is that it doesn’t work the hips enough and primarily is over working the thigh (Quadricep) muscles. This create muscular imbalance. Going shallow on a squat also means people can overload the weight or volume of reps, further adding to the imbalance. There are a few occasions where you need to measure your range of motion on a squat but for most people getting below parallel should the the goal.
Weight on the toes – Similar to too shallow a squat weight going onto the toes sometimes to the point where the heels come up puts an incredible strain on the knees.
Knees caving inwards – If knees are coming together on a squat we are again not engaging hip/glute muscles. In addition it puts strain on the lateral and medial ligaments of the knee. This is the same problem if someone’s feet turn out too much and their knees don’t track in line with their toes.
Causes of these problems are usually a result of lack of mobility through hips and ankles and/or a lack of glute engagement/strength. Listen to your coach when you squat and see if you have areas to improve.
You need to be able to squat in life. Especially if you plan on being able to get up and down off the toilet when you get older.