This style of lunge is actually slightly better than the forward lunge when it comes to building muscle, partly because it's harder to compensate with the lower back, so your form is better.
If your goal is to build your quads, this reverse lunging style also beats the forward lunge, which is better for glutes and hamstrings.
Use these exercises to strengthen your grip, crush rocks, and punch through walls. Or, you know, just lift heavy stuff while keeping your hands healthy.