Starting Strength, 3rd Edition - Mark Rippetoe [126]
Let’s review the angles involved in the pull and see what varying them does to the bar path. The knee angle, hip angle, and back angle are the same for the power clean’s pull off the floor as for the deadlift.
Figure 6-22. The angles for analyzing the power clean are the same as for the deadlift or any pull from the floor: the hip, knee, and back angles.
The correct starting position facilitates an efficient pull. For example, when the knee angle is too closed, as when your knees are too far forward, your back angle will be too vertical, placing your shoulders behind the bar and your hips too low. Two possibilities exist for the next action on the bar, and in neither of them can the bar come up in a straight line (Figure 6-23).
First, the bar can move forward to get around the knees. This usually occurs only with lighter weights. Pulled forward around the knees this way, the bar will be too far out in front – off-balance forward – as it approaches the jumping position, and the lifter will have to either pull it back in or follow it forward by leaning into the bar or jumping forward at the rack position. Second, the bar can move back toward the mid-foot as it comes off the floor. This is what usually happens with a heavy clean. The pull starts, balance is off forward with the weight on the toes, so the bar gets pulled back into balance over the mid-foot. The knee angle opens and the back angle becomes more horizontal as the bar curves back into balance during the first part of the pull, below the knees. A common complication of this position error is that the back angle overshoots equilibrium with the pull, becoming more horizontal than it should. This angle throws the shoulders too far forward and causes the bar to follow the shoulders, again making the bar run forward of the mid-foot balance point. Better lifters can stabilize their back angle before it becomes too horizontal, but they won’t need to if the bar comes off the floor in an efficient vertical path in balance over the mid-foot. The correct starting position facilitates this balanced vertical bar path.
Figure 6-23. Bar path errors caused by the knees-forward/hips-down start position. (A) The bar goes forward around the knees, usually only at light weights. (B) The bar comes back toward the mid-foot, having been pushed too far forward by the knees. Neither bar path is vertical off the floor. (M.A. = moment arm)
You correct both errors (letting the bar move forward or backward) by raising your hips and pulling the bar back into your shins, thus putting the bar in the correct line of pull before it leaves the floor. You might need to think about keeping your weight back on your heels, especially if you are wearing weightlifting shoes with higher heels. Shoes are an important piece of personal equipment, but if they throw you into a forward position before you start the pull, they will create more problems than they solve. Remember to get back off of your toes and onto your mid-foot before you start the pull.
So, one extreme occurs when the knee angle is too closed, the back angle is too vertical, the shoulders are behind the bar, and the hips are too low. The other extreme occurs when the knee angle is too open, the hip angle is too closed, and the back is nearly parallel to the floor. This set of angles (much less commonly observed due to the tendency of most people to start with their hips too low) presents a different problem.
Figure 6-24. The hips-too-high starting position. Even with the bar in the correct place over the mid-foot, the shoulders will be too far in front of the bar. This position causes the bar to swing away forward to the normal pulling configuration, where the humerus is stable at 90 degrees to the lats, leaving the bar out in front.
Here, the quadriceps muscles of the thighs have essentially been