Lower back pain during and after squat work sets

[ComeAtMeBro]

My back feels fine until I put my belt on for my workset, during my worksets the bar slips a bit and my knees cave in loads, is the bar slipping cos my backs rounded and the back pain and my knees are caving loads? I dont really want to carry on squatting until i've fixed the problem

edit: didnt realise how many squat check threads there are, i'll read through and take some pointers from people with similar problems

[Tom Campitelli]

Yep. Lots of squat checks here. Post a video if you don't find your answer.