Starting Strength

barbell exercise is, they can be damned tough on the feet and knees for novices, and they are not weight-bearing in the sense that the whole skeleton is loaded with a bar on the shoulders. In contrast, the squat uses all the posterior chain muscles, uses the full range of motion of the hips and knees, has the stretch-shortening cycle inherent in the movement, and can be performed by anybody who can sit down in a chair, because we have very light bars that can be increased in weight by very small increments.
    The term “posterior chain” obviously refers to the anatomical position of these muscular components. It also indicates the nature of the problems most people experience under the bar, trying to improve their efficiency while squatting. Humans are bipedal creatures with prehensile hands and opposable thumbs, a configuration that has profoundly affected our perception as well as our posture. We are used to doing things with our hands in a position where our eyes can see them, and we are therefore set up to think about things done with our hands. We are not used to thinking about our nether regions, at least those unrelated to toilet functions. The backside of your head, torso, and legs are seldom the focus of your attention unless they hurt, and they remain visually unobservable even with a mirror. The parts you can see in the mirror – the arms, chest, and abs, and the quads and calves if you’re wearing shorts – always end up being the favorite things for most people to train. They are also the easiest parts to learn how to train because they involve or are facilitated by the use of our hands, and we are very “handsy” creatures.
    The hard parts to train correctly are the ones you can’t see. The posterior chain is the most important component of the musculature that directly contributes to gross movement of the body, as well as being the source of whole-body power. The posterior chain is also the hardest part to learn how to use correctly. This would be easier if you didn’t have any hands: how would you pick up a table without the ability to grab the edge of the thing and lift it? You’d get under it and raise it with your upper back, or squat down and drive up with your hips against the undersurface of it, or lie down on your back and drive it up with your feet, because those would be the only options open to you. But your hands shift your focus away from these options and enable you to avoid thinking about them at all. So posterior chain matters remain largely unexplored by most people, and this makes their correct use a rather groundbreaking experience.
    You will find that the posterior aspects of squatting and pulling present the most persistent problems, require the greatest amount of outside input from coaches and training partners, and will be the first aspects of form to deteriorate in the absence of outside reinforcement. For coaches, the posterior chain is the hardest part of the musculature to understand, to explain, and to influence. But it is also the most critical aspect of human movement from the perspective of athletic performance, and the mastery of its lore can determine the difference between an effective coach and a slightly-more-than-passive observer, between an effective athlete and one who merely moves.
     
    Much is made of “core” strength, and fortunes have been made selling new ways to train the core muscles. A correct squat perfectly balances all the forces around the knees and the hips, using these muscles in exactly the way the skeletal biomechanics are designed for them to be used, over their full range of motion. The postural muscles of the lower back, the upper back, the abdominals and lateral trunk muscles, the costal (rib cage) muscles, and even the shoulders and arms are used isometrically. Their static contraction supports the trunk and transfers kinetic power from the primary force-generating muscle groups to the bar. The trunk muscles function as the transmission, while the hips and legs are the engine.
    Notice that the “core” of the body is at the center of the squat, that the muscles get smaller the farther away from the “core” they are, and that the squat trains them in exactly this priority ( Figure 2-2 ). Balance is provided by the interaction of the postural muscles with the hips and legs, starting on the ground at the feet and proceeding up to the bar. Balance is controlled by a massive amount of central nervous system activity under the