saw Kai doing them on youtube but he was more inline with the bb,not as far forward.thought they were just called split squats.seems to hit outter quads pretty heavy,no?
I think the target muscles are all about the foot stance rocco. You can vary your position to hit different areas. Key thing is to find a form that works for you since it's a fairly awkward exercise to begin with. You can always do what Arnold did when trying a new exercise: do a 10 x 10 with it and see where you're sore the next day
Front foot pointing strait ahead hits the outter quad very good. Rear foot at a 45 degree angle to the front tears my inner thigh up. But yea focus on the foot position to get what you want out of these.