I'm 5'9 40 yo and weigh 150 pounds with 15% bf. After 1 bulking cycle, currently slowly cutting with a goal of 10-12% bf.

I tweaked my back a few months ago while squatting and deloaded to 135 placing special attention on proper form. I got up to 185 but after the workout my lower back was sore. Not sure if it's the muscles or the bones, it was more of a dull pain but I don't want to take chances.

I want to increase reps at lower weight. Lets's say I'm now at 5x7 @ 170 pounds. If I can get to 5x10 @ 170 then I'd go to 5x7 at 175 and again slowly increase my reps. I want to build up my lower back strength as it appears my legs are way ahead of my core.

Is this a sound strategy or am I pissing against wind here?