battling sciatica (caused from butt wink) and some other lower back injuries (caused from cliff diving and prolonged with over zealous raining) so I started box squating to limit ROM and also keep ROM the same each rep.
I have been lowering the box as my hips would allow. I believe this to be competition height.
What does every body else think? Also any form issues?
EDIT: I dont normally move that slow but squating every day caught up to me a bit and I was moving a bit gingerly…
Depth looks good to me, I would give you a white light! But you really should be sitting back onto the box, not just touching then ascending. Watch any Westside video on youtube and you’ll see what I mean.
Thanks for the white!! Just need 1 more 
Depends on your goals, they do it for their reasons but I use the box to limit ROM and I want the rest of the squat to mimic a squat as much as possible.
So for me leaning back doesnt make much sense.
I also think the box should be used to stop momentum (eliminating the stretch reflex) while still mimicking the squat as much as possible. So once again the lean back is lost on me.
You’re not going to eliminate the stretch reflex that way. You’re still supporting the weight with your legs which means you’re still storing the energy. Granted, not as much as a free squat. You have to release the hip flexors and then all your weight will be on the box.
Squat to a chair like your lifting or whatever’s handy right now. Then lift your knees. All your weight is now on the box and all the energy you built up on the descent has dissipated through the chair. Do this when you box squat, except you don’t actually have to lift your knees. That’s just to teach you how it feels.
I’ve seen Stan Efferding do this thing where he descends to a box and as soon as he touches it he explodes up. Just throwing that out there.
Learn something everyday, this explains why they lean back.
This is what happens on the heavier reps
Regardless of how you box squat, your descent is going to be slower so there’s no bouncing off your ankles and knees so to speak like an oly lifter. This can help teach you to load your muscles as you descend instead of dive bombing and catching yourself in good position in the bottom to sling yourself back up. Both are valid styles and everything inbetween from what I’ve noticed.
Yes!!! The are not rocking for momentum off the box! Many people make that mistake and I can see why when they see the videos.