Should You "Put Your Back Into It"?

I love this picture of my cousin Chris in a comfy resting squat on Gavleston Beach.

My biomechanical experiment has gone on too long. It's now time to put my ideas into action. The proposal: I have heard coaches say repeatedly to "activate the posterior chain by engaging the lumbar spine in order to keep the hamstrings active". In doing this, supposedly, you will get more force out of a lift and will protect your spine from injury. I could not find one scientific, peer reviewed study that demonstrated this in the form and by the standard that Crossfit and Olympic lifting demand. I propose to conduct an EMG test of the posterior leg, hip extensors, lumbar spine, and abdominal muscles in order to truly understand if and how this activation and protection is achieved. In a brief correspondance with Dr. Lon Kilgore at Midwestern State University, I learned that little research has been done of the squat lift in its full range of motion. My experiment would have experienced Olympic lifters perform a body weight squat beyond a 90 degree knee angle, once in lumbar extension, and once with slight lumbar flexion, or posterior pelvic tilt. Force and angles will be measured and quantified to determine differences in force outcomes. The experiment will be conducted at the Timpany Center in San Jose, monitored by Dr. Kao of SJSU.

Okay, on a lighter note, this is interesting to me for several reasons. I had very limited range of motion in my squat (and everything else) before starting Crossfit, mostly because of my technique. Though I saw better results when I changed the way I did a squat, I couldn't explain exactly why this would both help me increase the load I could lift and help save me from injury. My mom asked me, "Why would you want to squat 200+ pounds or lift 300+ pounds off the ground?" Umm... why not? But seriously, shouldn't we try to reach our physical potential? And what is that? If we truly stress the system, can we learn why these muscles are here and those there? Do strength and stability really work together? Is there an anatomical/biomechanical reason for anterior and posterior pelvic tilts? Is one more important than the other? These things I must know.