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.
The most underutilized pieces of equipment in most gyms are the dumbbells. Oh sure, you might see people pumping out a few sets of biceps curls, bench presses, or flyes, but in most gyms the dumbbell racks are primarily used as a place to lean against between sets of barbell squats or benches.