Starting Strength

the glutes, the sacrum, and the lowest part of the lower back – that a coach can touch with the hand and identify to the trainee. The coach can place his hand on this area and tell the trainee to “push it up,” a tactile cue that greatly improves the efficiency of the contraction of the muscles that produce the movement. The front squat has the hips directly under the bar, or as nearly so as possible – a position which presents no surface for cueing. The column of the torso stops at the chest and shoulders, and these, along with the elbows, are the surfaces that get cued. A focus on the chest, shoulders, and elbows – driving them up, even as you lower the bar – preserves the vertical position that is so critical to finishing a heavy front squat. This focus is in stark contrast to the squat’s, both in position and in the way the movement is visualized. The differences are great enough that they should not get confused, but they quite often do, and for this reason the front squat is best left alone until the squat’s movement pattern is thoroughly embedded.
     
    Since the front squat has such radically different form, you might expect that it should produce a different result than the squat. It does, for the back, hips, and legs. The vertical back position of the front squat seems like it would result in a more direct compressional load on the spine than the squat’s more horizontal angle would produce. This is partially true. The lower back is in a nearly vertical position, but the upper back has a much tougher job because the load it is holding up is farther away, forward. The bar in a back squat, low-bar or high-bar, sits right on top of the muscles that are holding it up. The front squat places the bar all the way across the depth of the chest, which in a bigger guy might be 12 or more inches. This distance is a moment arm that presents a mechanical challenge to the muscles that maintain thoracic extension (it is very common for lifters to get pretty sore between the shoulder blades when first starting the exercise). And since the bar is forward of the hips, too, there’s also a moment arm against the hips, although probably not as long as in a squat, and certainly under a lighter load. So while the lower back is vertically positioned, your thoracic erector muscles have a lot of work to do. What actually happens is a gradual shift from compression to moment, from low back to upper back, so things are not as simple as they may seem. The load on the lumbar spine in the front squat is friendlier (because it will be lighter) as long as the upper erectors can maintain position, and for this reason, many people find front squats to be easier on the low back. But this also means that the front squat is a less effective back exercise than the squat.
    When you front-squat, don’t worry about your back; worry about your knees. To facilitate the vertical back, they have to track forward so that the hips can stay directly under the bar. This means that the shins will be much more horizontal at the bottom of the front squat, with a closed knee angle, dorsiflexed ankles, and a lot more moment force operating along the tibias than there is in a squat. For most people, these factors will mean contact between calf muscles and hamstrings at the bottom, and sometimes a rather dynamic loading of the Achilles tendons and quadriceps. For some people, this closed knee angle will create enough “wedging” on the posterior knee cartilage that it can produce instability and injury, a situation that essentially never happens in a properly performed low-bar squat. For everybody, the job of opening the knee angle through a much greater ROM, with muscles working against more moment force because of a more horizontal shin, is much harder.
     

    Figure 7-10. The knee position in the front squat, necessitated by the vertical back position, produces a moment arm along the tibias, a phenomenon that is not significant in the squat. ( M.A. = moment arm )

    Since the front squat places the knees so much farther forward than they are at the bottom of the squat, the hamstrings are not nearly as involved in the hip extension. In the front squat, the vertical back and pelvic position and the acute angle of the tibias place the hamstrings in a position where the origin and insertion points are closer together, so the muscle bellies are shortened. If the hamstrings are already contracted, they cannot contract much more and thus cannot