Try OL squats (front squats), jefferson squats, hack squats, duck deadlift, one leg squat with dumbbel, etc, without a power rack is better no work to failure, is not needed and even counterproductive.
Front Squats put alot of pressure on your lower back if done wrong.
In my experience back squats (done badly) put more pressure on the lower back, as people make up for crap depth by leaning forward and Good-morning the bar up. Plus the position of the bar on back squats adds immediate pressure that’s just not present in front squats.[/quote]
As you said before, back squats DOES PUT A LOT OF PRESSURE IN YOUR BACK (pressed caps lock, too lazy to rewrite…) and put more pressure than front squat, the front squat must be done in the olympic stance, that way the body goes down with the torso upright, putting your ass between your legs as it goes to the hole, anyway you have as a back reliever the jefferson squat and the one leg squat, pistol squat, pyramid squat, zercher squat, and so on…