switching up my leg workout for growth

[wilk.daniel]

I have been killing my legs for about 6 months (only been lifting for about 8 months) after a few years of time off. My legs are not growing like my upper body, the definition is exceptional but I need some size. I follow a similar program as dorian yates with the high intensity low set count. It has done numbers for my upper body but I do not think it works as well for legs. my current program is

Warm up 2 sets leg extension then 3-4 sets real weight (preexhaust em)
warm up 2 sets on leg press then 3 sets heavy
hack squat 3 sets heavy
3 sets lying down leg curls
2 sets standing hamstring curls
and my calfs are fine and have been growing so i am not going to switch that up

What I plan on doing is
Warm up 2 sets leg extension then 3-4 sets real weight (preexhaust em)
hack squat 5-6 sets heavy
leg press 4-5 sets heavy
3 sets lying down leg curls
3 sets standing hamstring curls

basically switching up the order a little bit so i can go heavier in squats and adding more volume to the set count

Also 2-3 years ago I fell off a roof when I was roofing (ladder broke as I was stepping on to the roof I injuried my back and neck and was stuck to a bed for a few weeks popping pain pills just to sleep) and now my lower back hurts when I do BB squats or deadlifts and I do not want to Push its limits as I am afraid I might cause reinjury.

I will take suggestions on this routine/ anything to add

[silversv1k]

lunges ftw, do 3-4 sets and tell me how your legs feel the next morning lol