Low back pain

[The Mastiff]

Advanced lifter first time experiencing lumbar spine pain. Feels like l4/l5. Recently retooled my squat to sit back more and use less of a forward knee (as I should have been doing) due to stress on my patellar tendon, and now my low back has felt strained. Simple stuff like putting plates back on the tree hurts it. Bending down to stretch my hamstrings is also uncomfortable. Is the prescription more lifting and some posterior chain stretching, or a temporary layoff from squats/deads?

[damufunman]

How off was the knee position prior? I'm having similar too much knees issues with my squat. Had a coaching session a couple weeks ago where I was cued to get knees to position and maintain them there. Did volume squats (on TM) and my back was immediately sore after the last set, and was sore for a week. If you've been really quad-ing it up it might be that your back is quite detrained for the more horizontal back angle. Possibly lowering the weights a bit and doing a short LP back up might help.