Since you've already commented on your main issue (and you should review chapter 6 of SS:BBT on this topic, specifically Figures 6-44 through 6-45, and the surrounding text), I'll add that you should probably try a hook grip as well. Your set-up needs work since you pull three reps from three different positions. See the set-up procedure detailed in the link "About pulls from the floor" in the sticky at the top of this forum. You're hopping around at the top of each rep in order to lift the bar higher onto your choulder - remember, the bar is CAUGHT by the shoulder, not the hands. Go get the bar with the shoulder - forget about your hands. Finally: Shoes. Get some.