I don't know if what I performed yesterday was necessarily a "sumo" style squat, but I was brushing up on my WSB reading and decided it was time to bring my stance out much more then I had it, and my poundages sky rocketed. I think Im going to keep it out wide now for a while. It seemed to be less stress on my knees as well, because I felt the weight much more transferred to my glutes and hips.