The gluteus maximus is a primary mover of hip extension. Weak glutes mean weak extension. If this is you, then during the eccentric (lowering) phase of the squat there’s a good chance you’re going to start tipping forward. People talk a lot about core tightness and bracing the core as it relates to the forward lean. The first step to maintaining an upright torso is proper eccentric glute control. If you don’t have the glute strength to maintain and drive hip extension, then your lower back will kick in to compensate and guess what? It’s not really suited for the task. If your butt’s weak, your back’s going to hurt – plain and simple. So let’s work on some lunges in our off time to strengthen that booty!