The reverse lunge is all about acceleration and power generation. Compared to a regular lunge where you have to decelerate your body going forward, stop, and then push back up, the reverse lunge has a smooth "set-up phase" and a powerful push/drag action back to the starting position. This makes it a perfect weapon for power athletes who experience either low back or knee problems during regular squats.
By controlling the angle of the shinbone, or more precisely, limiting the forward knee movement, you make it easier on your knees. That said, you can allow more forward knee movement if you want to focus more on the quads.
From the bottom, power-generation phase, combine a push with the quads and a pull from the glutes and hamstrings. It's a common mistake to overly rely on the quads for creating the movement. If you want to limit the stress on the knee, you have to really use your hips as well.
In the video you'll see two different positions of the dumbbells. The rack position load is similar to a front squat and will activate the upper back and core to a greater degree. The hands-down position reduces some of the upper body focus and is a bit easier to perform for most people.