Starting Strength, 3rd Edition - Mark Rippetoe [37]
As noted earlier, stance width will influence knee position. For example, if you are tall with very long femurs and relatively narrow shoulders, you need a wider stance than is usually recommended. If you have a long torso and short legs (not that uncommon a body type), you will need a bit narrower stance than our rule of thumb would predict. Sometimes the foot angle needs to be adjusted for individual situations: if you are pigeon-toed, your foot angle will need to be slightly more forward-pointing than our model recommends, or more commonly, in the case of out-toeing, the feet will need to be pointed out more. These corrections are necessary to keep the correct neutral relationship between the femur and the tibia so that no twisting occurs in the capsular, medial, and lateral ligaments of the knee. Expect a closer stance to place the knees more forward relative to the toes, and a wider stance to place them farther back (see Figure 2-52). But again, shoulder-width heels produces the best effect for general strength training.
Figure 2-52. The relationship between stance width, stance angle, and knee angle. The wider the stance, the more the toes point out, due to the changing angle of the femurs at the pelvis as width increases. The feet keep the tibias rotated in line with the femurs – and keep the stress off the knees – by changing their angle to accommodate the rotation. As explained on earlier, the moment arm along the femur is calculated from the position of the bar over midfoot. The knee “sees” the moment arm from knee to bar and the hip “sees” the moment arm from hip to bar. (M.A. = moment arm)
A narrow-stance squat, such as that frequently pictured in the muscle magazines, develops an aesthetically pleasing set of quads. But since we plan to use the rest of the hip musculature, too, it seems unwise to omit it from the training program. It is very difficult for people of normal flexibility to get deep enough with a narrow stance, so the hamstrings are never engaged as fully as they would be with a more generalized wider stance. Also, the narrow stance does not involve the groin muscles, as discussed earlier. For this reason, it can be useful in the event of a groin injury and can be used for several weeks while the adductors are healing. If used all the time, however, narrow-stance squatting predisposes you to a groin injury due to the lack of conditioning for these muscles.
One occasionally sees powerlifters squatting with a wide stance and their toes pointing almost forward. Some really strong powerlifters do this to increase the joint tightness and resultant rebound obtained by placing an additional twist on the knee and hip ligaments. Some of the others do it because they are merely copying what they’ve seen the strong guys do. This is a practice best left to very experienced powerlifters. For you, it will be very important to have all the bones of the legs and hips in the best position to generate force without causing tendon and ligament problems. Here is a way to see this relationship: sit in a chair with your knees slightly bent and your feet out in front of you, without pushing hard on the floor. Put your legs together, and note that your toes are pointing straight forward. Spread them out wide and note that your toes are pointing out. In both positions, your feet naturally assume a position parallel to your femurs, and your knees are in an anatomically neutral position, with no twisting (Figure 2-52). As your knees point out, your toes point out. The wider the knees, the more the toes point out. As the knees widen, the femurs rotate externally, the tibias