Herniated Disk - Substituting Squats and Deadlifts

Ever since I herniated a disk, squats and deadlifts, no matter what I try in terms of using perfect form, lower weights, shorter ROMs, seem to just be a no go for me anymore.

It’s really frustrating because greater leg development is what I would like more than anything else. Now I would like to do the Velocity Diet workout routine, which calls for Romanian Deadlifts, Front Squats and Deadlifts.

Anyone here found any satisfying ways of substituting these lifts with other exercises? I would love any advice you could provide. I have tried doing things like single leg deadlifts (bodyweight), leg extensions, lunges, and a handful of other bodyweight exercises, but they just don’t seem to produce the same results as the traditional “big” lifts do.

I am sure there is a way, but I haven’t been able to find it yet. Advice from those who have found some success at attaining good leg development without squats or deadlifts would be greatly appreciated.

ps - my gym, at least for now, unfortunately does not have a trap bar