Squatting and Pelvic Alignment Control

To Mark and the Coaching Staff:

After providing my amateur feedback on these forums previously in addition to coaching myself and my wife out of necessity, there seems to be an issue that a lot of people share when performing low bar squats (and, to a lesser extent, high bar squats), but before I get into it... a fact check. I've tried to digest and retain what I can from SS:BBT and Practical Programming, but I may have missed this.

1. When performing a squat, the back, core and shoulders are largely responsible for maintaining a rigid spine in a neutral spinal alignment to facilitate the most efficient and safe biomechanical system to bear the forces involved in these movements and transfer force from the feet to the bar.
   
2. The pelvic angle should also remain neutrally aligned, as this affects alignment of the sacrum (which in turn feeds back up into the lumbar and thoracic) with the hips being the sole hinge point for the upper posterior chain, followed by the knees and ankles.

Here is what I've noticed so far, and what I have attempted to correct/coach:

1. My wife, due to posture, has a kyphotic (sp?) lumbar curve. It seems that the balancing force for pelvic tilt as it relates to the spine/upper body comes primarily from the frontal abdominals (more so the lower abdominals) against the spinal erectors. Is this true? If so, is attempting to coach a harder isometric effort in the frontal abdominals the cure for fixing this? Would the use of a lifting belt provide sufficient assistance for isometric contraction of the abdominals to correct?
   
2. The "ass back" cue in the low bar squat seems to cause a relaxation of the frontal abdominals and further contraction of the spinal erectors (causing unwanted pelvic tilt) during the beginning of the squat as the hips and knees unlock instead of allowing the hips, knees and ankles to hinge naturally. As I understand, this is bad for a number of reasons:

• Reduced efficiency of force transference.
• Increased risk for sacrum/lumbar spinal injury.
• Unwanted movement in the bottom of the movement as the pelvis rotates back into position (usually causing a forward bar path at the bottom). This movement and forward bar path causes obvious issues due to moment arm increase, and the pelvic rotation seems to remove a lot of the benefit of the "bounce" from elastic tissues in the posterior chain.

Assuming I am not horribly off in my assessment, where does one begin to coach this loss of isometric abdominal contraction out of a trainee?

The more logical explanation for her inability to maintain spinal extension is then the erector spinae muscles are either not strong enough or that she doesn't know how to keep her back flat during a pull. Since the lumbar muscles set the position of the lordosis, I am unconvinced that the abs -- the rotten sorry fuckers -- are responsible.

Well, then the failure is mine as a coach for not placing enough emphasis on lumbar isometric focused contraction.

Errata from my previous post... her posture issue is lordotic (not kyphotic), and the pelvic tilt is anterior rotation at the beginning of the lift resolving into posterior rotation at the bottom (causing slight forward travel in the bar path directly related to pelvic movement). You already caught it, Mark, but I figured I would add it for others viewing to negate confusion.