Have low back pain when squatting? There can be several reasons for this, but the first thing I check is your ankles. Limited ankle range of motion can alter how you squat and change your center of gravity, placing more strain on your low back. 

If you can’t squat deep without your heels raising or your feet turning out, chances are you are missing some ankle range of motion. The body loves to compensate, and just how it chooses to do it dictates where symptoms may develop. 

For example, if you squat and feel like you’re going to fall backwards, you will likely bend forward at the waist as a counter to the feeling of falling backwards. Like so:

That may be all well and good, but once you start loading this position with some weight, your back will have to work extra hard to get that weight back up. A quick test to see if the ankles are the problem is to take them out of the picture by buying back some range of motion and elevating your heels. You can stand on some plates or on something like shown below. If, with heels elevated, you can be closer to upright in your torso, chances are it’s your ankles to blame. See below:

So the short term fix would be to elevate your heels, or just not squat as deep. However, if you want to get into a deep squat (which I recommend for knee health), then you should prioritize mobilizing your ankles and getting some range of motion restored.

Here are two of my favorite exercises for this: