I recently saw a Physical therapist about my lower back issues and not being able to squat over 200 lbs without messing myself up in quite a while, and he thinks the cause of the issue is an extreme lack of flexibility/mobility. When I squat, I lose my arch near the bottom of the squat and by the time I am at parallel my back is basically rounded or in "flexion". This is probably why I can't squat without screwing myself up.
If any of you guys know of good hip mobility drills (thats what I need right?) or stretches that could help me out in maintaining an arched back throughout the squat, I would really appreciate it. I have been doing static stretching the past 5 months with some flexibilty improvement, but overall it is not good enough at all. Also, my hamstrings are still tight as fuck.
I will be doing more reasearch on this myself once finals season is over, but I'm hoping you guys might have some good info on this.