Starting Strength

hamstrings reach the limit of their ability to stretch, they become tighter and begin to exert more pull on both the knees and the muscles’ pelvic attachments. If your knees are not far enough apart, your thighs will also crowd your torso as you approach the bottom.
    There are two problems. First, your back muscles attach at the top of your pelvis, your hamstrings attach to the bottom, and the pelvis can pivot around the hips. So both the lower back muscles and the hamstrings can cause pelvic movement around the hip joints. The back muscles and the hamstrings are thus competing for control of your pelvis, and the back muscles must win if your spine is to stay efficiently rigid and safe. Second, if the femurs are too close together as you approach the bottom, there is not enough space between them for the torso to drop down low enough for a deep squat. The key is to position the femurs, the pelvis, and the low back so that the erectors and the hamstrings complement each other’s function.
    By shoving the knees out as you squat, while locking the spine into extension, you remove the tendency for the lower back to round. Shoving them out as you unlock at the top places the femurs in external rotation, and then the muscles that perform external rotation just keep the femurs in this position on the way down and up. The muscles that are stretched out when externally rotated then become active in the squat. If the knees are shoved out of the way, hamstring extensibility plays a minor role in the ability to assume a deep squat position. Since the hamstrings do not stretch out that much, most people are flexible enough to squat below parallel if they do it correctly.
    Usually, the biggest problem with back position is the trainee’s inability to identify which position the lower back is in. A lack of kinesthetic sense – the ability to identify the position of the body or a body part in spatial relation to the ground or the rest of the body – is very common. Some people have absolutely no idea that their lower back is rounded at the bottom of the squat, or that it is arched correctly at the top of the squat, or have any idea at all of what position their back is in. They cannot tell an upper-back arch from a lower-back arch, and the line between upper and lower seems to be blurred. If you ask someone with this problem to arch his lower back, he lifts his chest, or bends over from the waist, or performs a number of other interesting movements that have nothing to do with lumbar extension. Many people with inflexible hamstrings exhibit this problem, but not much hamstring flexibility is actually required to squat correctly, and many perfectly flexible people cannot assume a position of lumbar extension and hold it through a squat. Some people – mostly female, as a general rule – can place the lumbar spine into a position of overextension , and this is bad, too, perhaps potentially more dangerous than loaded lumbar flexion.

    Figure 2-37. Lumbar overextension ( female model ) is not the correct back position to use in the squat. It indicates a failure to engage enough abdominal contraction to support the spine from the anterior.

This occurs when you fail to use your abs to provide the anterior support necessary to counter the extension provided by the erectors. But this overextension is far less common than the simple inability to maintain lumbar extension against a heavy load in the squat or deadlift. As it turns out, if you can’t make a voluntary concentric contraction of the lumbar erectors – the movement commonly understood as arching the lower back – then you have no voluntary way to keep the lower back in extension when this position gets hard to maintain. Please read this again, and understand this point: an overextended lumbar spine is not the position you use to squat. But if you can’t voluntarily arch your lower back, you can’t control the erectors well enough to keep the spine from flexing at the bottom of the squat or the start of a deadlift or clean.

    Figure 2-38. The easiest way for a coach to identify spinal extension – arching the back – is to look for wrinkles that appear in the cloth of the shirt as the top and bottom of the back get closer together.

    The key to learning the correct position for the lower back is to assume a position that is correct, and then memorize the way it feels so that you can reproduce it every time. The best way to do this is to lie down on your belly on