THE STATIC/RELAXED PHASE (BREAKING THE ECCENTRIC-CONCENTRIC CHAIN)—SITTING ON THE BOX
The static/relaxed phase begins when the backs of your legs come in contact with the box and you’re sitting down completely on the box by rolling back onto it. (Note: This does not mean rocking on the box, dropping down on the box, bouncing off the box, or doing a touch-and-go on the box). You should immediately release (relax) the hip flexors while keeping the rest of your body tight, especially keeping the remaining squatting muscles of the posterior chain very tight during their brief static contraction on the box (this will preserve stored kinetic energy and stretch reflex not dissipated from the collision with the box). You have now broken the eccentric-concentric chain. Your back should remain arched, the hamstrings and glutes stretched, and the abdominals as tight as possible. The shins should be straight up and down (perpendicular), or even past perpendicular, placing all the work that’s about to happen within a matter of a second or two when you begin the concentric phase of the lift directly on the hamstrings, glutes, hips, and spinal erectors (lower back). The momentarily relaxed state of your hip flexors and the momentarily static, stretched state other squatting muscles of the posterior chain are about to be overcome by being engaged all in unison in an explosive dynamic contraction in which you leg-curl yourself off the box into the concentric phase of the lift. These static/relaxed-overcome-by-dynamic-work methods are the cornerstone of why box squats are such a powerful lift for the development of absolute and explosive strength. Now it’s time to jump.
THE CONCENTRIC PHASE— ASCENDING FROM THE BOX After you pause on the box, you will begin the concentric phase of the lift by ascending from the box in an explosive manner in which you simply reverse the sequence of movements in the eccentric phase. This means the head moves first, followed by the glutes and hips. Specifically, begin by being sure your core is tight by pushing your abs out against the belt, then driving the head and upper back into the bar, which engages the spinal erectors and allows you to forcefully flex the hips, glutes, hamstrings, abs, and finally quads while you arch the upper back, drive the feet outward, push straight up into the bar, then jump off the box by leg-curling yourself up.
Now that I have taught you correct Westside box-squatting technique, it’s time to teach you some fundamental Westside box-squatting methods, so you can put your newly acquired skills into practice in your strength-training program.