For the longest time, I could never keep my butt down on bench press. I used the excuse of my extremely long tibias making it about darn near impossible, and while they do make it a bit more difficult, there was a fix. I tried different setups with my foot position, I worked on increasing my arch, I tried flat shoes versus heeled shoes, lifted on commercial gym benches versus competition benches, but none of that seemed to really matter. The route cause was the cueing of my leg drive. Two main things were wrong:
1.) I would drive through my heels, pushing straight up.
2.) And even when I fixed that, I would still think of leg drive as this push with my legs as I pressed.
So what did I do to fix the issue?
1.) First and foremost, constant tension was critical. Leg drive should not be something you initiate just as you press, but instead something that is present through the entire lift. From the time I start the downward motion until the moment I rack the bar, I am always driving with the legs. The only small change is I may be driving at 50% effort during most of the lift, but during the press I increase to 75%. And notice I didn’t say 100%. You are not trying to heave the bar up with your legs. The two main things you are trying to accomplish with leg drive is increasing tension and creating inertia moving back, not up, which leads me to the next fix…..
2.) Leg drive is back, not up. What you are trying to essentially do is slide back into the bench. But because you are holding weight and have your upper traps dug into the bench, what happens when you drive back is those traps stick into the bench, drive down into the bench, which then has the opposite reaction of driving the bar up. Just like the feet pushing into the floor on squat and deadlift to create the force to drive the bar up, the upper back drives into the bench to apply force in the opposite direction to move the bar. Your legs do not move the bar, they just create the tension and inertia to drive the upper back down. So when I drive with the legs (reminder from point #1 that this is a consistent drive throughout the entire range of motion), what I am thinking about is trying to slide my feet forward and out. Almost like I am trying to push my pinky toes through the front of my shoe. This force in return should cause your body to want to slide back into the bench. If done correctly, the butt really shouldn’t move, as there should be little to no vertical force with the leg drive, but rather horizontal force.