Originally Posted by
Dalton Clark
While what you say is true (that having a flatter back will reduce pulling ability), it is better to pull correctly and safely than attempt to heave up 400 pounds with your lower back. If you slow down your video to .25 speed, you can see a major issue at the start of your lift. The first thing that your body does is round the lower back and this continues until halfway through the lift. Keep your hips high and get your chest and shoulders through the bar. The reason the bar feels like it is forward of the mid foot is because your center of mass is well behind where it should be. Also, if you dip your hips like you do at the start of every lift, you lose all of the tension in your hamstrings, forcing you to use your back to lift the weight which isn't what you want.
Assistance exercises: if you can really focus on getting your chest through and shoulders in front of not over the bar, rack pull will help with this. From about as low as you can go.