In my squat I go down as far as possible(in the hole resting on my calves). The problem is, my lower back rounds out at the bottom. What I noticed is that squatting like this doesn't bother me directly(i.e. during or immediately after squatting) rather, my lower back really hurts after standing or sitting for periods of time.
When standing this also bothers my hips. I went to my Doctor and was told that there is nothing really wrong with my back or spine. She also checked my joints and she said they're all fine. So, anyway, I have been doing the Agile 8 to improve my flexibility and also been stretching out my hamstrings and hips most days. Also, it seems as though my stomach sticks out kind of far, even though I have a low body fat, could this be tight hamstrings pulling on my pelvis causing this? Also, in addition to the Agile 8 and stretching, is there anything else I should be doing for my flexibility?