When you have low back issues, this a great alternative to the squat. The classic version of the split squat is good, but if you want to increase the stress level then elevate the front foot with a step and go deep on each rep.
This variation is one of the best out there for safe leg development. You get a lot done with a low amount of risk. This choice is a slam-dunk if you have back issues but still want to train hard.
You can train this exercise for different purposes by varying the execution, but in the video I hold the dumbbells in the rack position. This is more similar to a front squat and the benefit is that the upper back has to work a bit more.