I took a mirror off my wall in my apartment and set it on the ground to watch my squat form. I noticed that as I approach parallel and below, I develop a posterior pelvic tilt and my lumbar starts to round as it follows downward. The rest of my spine is neutral and looks great, it's just that my butt starts to round down at the bottom.
Eric Cressey... Mike Robertson... any other biomechanic buffs?
What could be the potential cause here? I'm sure you'd like to see a picture to know for sure, but I'm wondering if you could take a guess.
My knees and feet look great, my stance is plenty wide enough, my head and chest are up, my heels are solidly on the ground. Everything is textbook until I hit parallel.
I'm pretty sure gluteal tightness is not the cause, as I feel pretty flexible there, but I'm stretching them anyway. Right now I'm focusing on box squats and some gluteal activation work. Am I missing anything??? Any ideas for glute work that I may not be doing?