I'm 21, 5'9" 160 lbs. I ruptured a disc in my back (L5,S1) when I was 16 years old while lifting weights. I haven't been able to do much lower body work since the injury...it's something that will be with me forever. All I can do to help it is strengthen my core (abs, lower/upper back, etc). I know how important it is to do squats, deadlifts, etc. to help boost overall strength. I started lifting very hard again 6 months ago, but I have only been doing upper body. I tried doing squats one day and I could barely sit or drive for two weeks after that and was in constant pain. I haven't been going up much lately in my lifts, so I want to try some lower body stuff. I can do calf raises & leg extensions, but not leg press, squats, dead lift, or power cleans. I'm taking creatine, protein, BCAAs, multi vitamins, and I am eating right. I've been mixing up the lifts in my workouts and I've been working hard. Are there any specific lifts that you can recommend for my lower body that will help me increase my overall strength? Also, here is my general workout each week:

Monday:
DB press - 2x8, 5x5
Close-hand BP - 4x6
Tri Extensions - 6x6
Flys - 4x8
Dips - 4x15
Barbell curls - 2x8, 5x5
DB curls - 4x16
Reverse curls - 4x8
Wrist curls - 4xfailure
Ab routine

Wednesday:
Arnolds - 2x8, 4x6
Military Press - 4x8
Lat pulls - 4x8
Row machine - 4x8
Bent over rows - 4x8
Front/Lateral raises - 4x10
Upright rows - 4x8
Ab routine

Friday:
Flat Bench - 2x8, 5x5
Decline BP - 5x5
Incline DB press - 4x8
Tri Extensions - 4x8
Nose breakers - 4x8
Dips - 4x15
Curlbar curls - 4x8
DB curls - 4x16
Reverse Curls - 4x8
Wrist curls - 4xfailure
Ab routine

Please let me know if you see something that needs changing. Also, I haven't been able to work on my traps because of another injury. If there are any lower body exercises that you guys can recommend, I would greatly appreciate it. Also, let me know what you think about my workout plan.

Thanks!