Started 5x5 a month ago. After getting to 55kg squats I started

>>36554423
either fix your ankle and hamstring flexibility, stop squatting on plates and work towards a proper highbar squat
or squat low bar and also get rid of the plates.

read SS, especially the part about knees traveling forward

>>36554453
Oh I only got the plates, because I read that it could help.

>>36554423
Do you want to fix your squat or the knee pain? Your squat looks fine, I'd just get used to not using the plates (can be dangerous at higher weight, if you're serious about lifting buy some oly lifting shoes) and lock out at your hip joint at the same time as your knee joint. As for the knee pain, I'd warm up more and/or get some knee sleeves.

>>36554423
your ankles are stiff as fuck