Ok had a kid (I mean 16 yrs old 115 lbs and the lankiest kid at that age I have ever seen) that got a trainer I think it was a good choice on his part. Only saw the stuff the trainer who is a big guy for his height. I think he's more bodybuilder than powerlifter but he's pretty strong. only saw the work by the squat rack. He had the kid doing Squats with just the bar to teach technique I totally approved. Then RDLs he had the kid doing it with 55lbs so that he gets the correct range. He had him have his toes on top of 10lb plates saying ti teaches him to put his weight on his heels. Well the kid was crazy tight and lacking flexiility but had a serious bow in his back from it. So I would think that lifting your toes would increase the bow....... but I will admit by the third set the bow was seriously less severe. Basically was what he was showing the kid to do does it make sense.