Front squatting onto a box is a stone bitch. Congratulations on selecting one of the most awkward squat-type lifts I have ever experienced.Front squats really get moving with a dip and bounce out of the hole- something you just can't do with a box. Generally speaking, unless your stance is very wide, you will not be able to sit back like you would with a back squat lest the bar pop off your collar. Front squatting is inherently more of a sit-down groove because of the upright posture you have to maintain to keep the bar in place. While you should push your knees out on the way down to load the tension in your hips/hams, your knees will come forward some when you front squat.
In that vein I screwed up my back the very first time I tried these with pretty low weights. I hit the box too hard and the bar jumped a little off my shoulders and crashed back down, put me out of commission for a couple of weeks. If I had it to do over again and was forced to do it I would start with real low weights until I had the movement grooved. But I won't be trying it again.
i....like....love to do front squat to a box. i've worked up to 605 and felt they have really increased my back squat. i rotate every other week with front and back squats. most importantly doing heavy front squats to a box has engrained initiating the ascent with my hips, really forcing the knees out and getting the hips through fast.
i've posted this before but this isn't awkward and i think this is a sufficient weight to be beneficial:)
i stopped doing them at that time because i was training for a comp and needed to concentrate on my competition squat. i kinda got obsessed with getting my front squat numbers up and i actually lost some of my back squat technique. i really enjoy doing them and will probably get back to doing them heavy but won't spend as much time on them. I'll rotate them in with front squats to pins, box squats, full squats, full front squats, paused front squats and zercher's off pins. these are my bread and butter movements.