Articles
Pressure vs Balance in the Snatch & Clean Pull
January 16 2017
January 16 2017
Confusion abounds in the land of the internets when it comes to ideas of balance and pressure on the foot during the Olympic lifts. Cues get misinterpreted as descriptions of fact, terminology is vague or misused, communicating concepts and translating them into feelings is tricky, and of course sometimes people just don’t know what they’re talking about.
I see lifters looking like their feet are made of rocking chairs, lifters who believe the heels should never lift from the floor, and lifters who believe that being extended on the balls of the foot is the same thing as the weight shifting forward over the foot.
Let’s clear up the misconceptions and sort out the facts so the pull of your snatch and clean doesn’t have to be some kind of suspenseful mystery each time. The goal here is to give you all this information so you can gain enough understanding and the resulting confidence to never think about it again during a lift.
Basic Concepts
Center of Pressure (CoP) Basically, this is where the pressure is centered on your foot. If you lift your toes and rock back onto your heels, the center of pressure is somewhere on your heel. If you stand on the balls of your feet, the center of pressure is somewhere in the balls of your feet. Simple.
Center of Mass (CoM) This is simply the point somewhere in the barbell-lifter unit around which that total mass is centered.
Line of Gravity (LoG) The line of gravity is a vertical line that passes through the center of mass—this will show you where the combined center of mass is balanced over base of support, i.e. the foot. For example, if you stand still balancing on the balls of your feet, viewing you from the side, the line of gravity would pass vertically through the balls of the foot. If you stand normally, the line of gravity will pass somewhere slightly behind the middle of your foot.
Area of possible balance and ideal location of balance over the foot
Alignment & Divergence: Stationary & Moving
This gets more complicated when we introduce quick and fairly complex movement, as well as an additional chunk of mass that is connected but not fixed in a static position to the lifter. Fortunately, we can basically disregard the barbell for our purposes here and just assume that the lifter is controlling the bar and moving it properly to maintain optimal balance. That allows us to focus on the feet, or really the foot, since all we’re concerned with here is where balance and pressure are in a fore-aft direction.
Above I said if you stand still on the balls of your feet, the line of gravity will pass through the balls of your feet—this should be intuitive to you since you’re standing still and balancing over that point. That’s also where the center of pressure will be—it has to be in order to support this balanced position.
Now, if I told you to jump backward and tell me where you felt the pressure on your foot right before you left the ground, you’d tell me the balls of the foot again—because that’s how human beings jump, with plantar flexion that naturally accompanies hip and knee extension. But you went backward—so we know the center of mass was behind that point, which means also that the line of gravity was behind that point.
In other words, if we’re standing still and balanced, the center of pressure and line of gravity will be aligned—they have to be or instead of being balanced, we’d be falling forward or backward. However, if we’re moving quickly enough, the center of pressure and line of gravity can diverge, just like they did in the backward jump. In the pulls of the snatch and clean, where the pressure is on the foot in the top of the pull (balls of the foot) is not necessarily the point we’re balanced over. We can do what we did with the backward jump and direct our center of mass separately from the center of pressure (or, more accurately, keep it in the same place as the pressure shifts forward on the foot).
The Pull
In the top of the pull of the snatch or clean, lifters will be extended onto the balls of the foot to various degrees, but in virtually every case, the heels will not be in contact with the floor. This has been misinterpreted many times as meaning that the lifter’s balance (LoG) has shifted forward to the balls of the feet, and is therefore a mistake. However, if the pull is performed properly, the lifter’s balance will remain in exactly same place over the foot as the ankle extends—a little behind mid-foot—so that the system’s center of mass remains in the same place.
It should be very clear from this photo that the combined mass of the barbell and body are not centered directly over the balls of the foot, but a point farther back.
That is, as the lifter moves from the starting position into extension and back down into the receiving position, the combined mass of the bar and body, despite seeming to move all over the place, are always still balanced over the same place (at least on average). We know this is true if a lifter lands in the same place he/she began and is balanced when receiving the bar (we know this is not true if that lifter instead lands in front of or behind the place in which he/she started, or is unbalanced when receiving the bar, i.e. falling over).
(This can get confusing in the case of a backward movement of the feet without an equal backward movement of the rest of the system—see this article for more on that issue.)
Let Nature Take Its Course
What I’m about to say may seem to make no sense after I just spent 4 million words explaining this all—let this happen naturally. The idea here is to understand conceptually that feeling the pressure on the balls of your foot does not necessarily mean your center of mass has shifted over that point, which we would not want in a snatch or clean, and then to trust the body’s process of extending to produce force.
In other words, your job in the pull should be comprised of two simple tasks: staying balanced over the same place (line of gravity slightly behind mid-foot) and producing as much force as possible against the ground.
In the moment you separate the bar from the floor, you’ll likely feel the pressure on the foot slightly more toward the balls of the foot than the heels because the bar will be starting approximately over the balls of the foot and represents a significant chunk of the combined mass. You’ll quickly shift back slightly as the bar moves toward the knees to establish the balance over the whole foot that we then want to maintain throughout the lift—this again will mean the LoG is slightly behind mid-foot, meaning you’ll feel pressure on both the balls of the foot and heel, and may feel very slightly more pressure on the heel. As you finish the extension, the pressure on the foot will shift forward quickly to the balls of the foot exclusively—not because you and the bar are moving forward, but simply because the heel is rising off the floor.
If you simply focus on preserving the balance over the whole foot and driving straight up with the legs, this process will essentially handle itself. If you find yourself jumping forward or backward, you know your balance is shifting rather than staying in the same place.
I see lifters looking like their feet are made of rocking chairs, lifters who believe the heels should never lift from the floor, and lifters who believe that being extended on the balls of the foot is the same thing as the weight shifting forward over the foot.
Let’s clear up the misconceptions and sort out the facts so the pull of your snatch and clean doesn’t have to be some kind of suspenseful mystery each time. The goal here is to give you all this information so you can gain enough understanding and the resulting confidence to never think about it again during a lift.
...your job in the pull should be comprised of two simple tasks: staying balanced over the same place and producing as much force as possible against the ground.
Basic Concepts
Center of Pressure (CoP) Basically, this is where the pressure is centered on your foot. If you lift your toes and rock back onto your heels, the center of pressure is somewhere on your heel. If you stand on the balls of your feet, the center of pressure is somewhere in the balls of your feet. Simple.
Center of Mass (CoM) This is simply the point somewhere in the barbell-lifter unit around which that total mass is centered.
Line of Gravity (LoG) The line of gravity is a vertical line that passes through the center of mass—this will show you where the combined center of mass is balanced over base of support, i.e. the foot. For example, if you stand still balancing on the balls of your feet, viewing you from the side, the line of gravity would pass vertically through the balls of the foot. If you stand normally, the line of gravity will pass somewhere slightly behind the middle of your foot.
Area of possible balance and ideal location of balance over the foot
Alignment & Divergence: Stationary & Moving
This gets more complicated when we introduce quick and fairly complex movement, as well as an additional chunk of mass that is connected but not fixed in a static position to the lifter. Fortunately, we can basically disregard the barbell for our purposes here and just assume that the lifter is controlling the bar and moving it properly to maintain optimal balance. That allows us to focus on the feet, or really the foot, since all we’re concerned with here is where balance and pressure are in a fore-aft direction.
Above I said if you stand still on the balls of your feet, the line of gravity will pass through the balls of your feet—this should be intuitive to you since you’re standing still and balancing over that point. That’s also where the center of pressure will be—it has to be in order to support this balanced position.
Now, if I told you to jump backward and tell me where you felt the pressure on your foot right before you left the ground, you’d tell me the balls of the foot again—because that’s how human beings jump, with plantar flexion that naturally accompanies hip and knee extension. But you went backward—so we know the center of mass was behind that point, which means also that the line of gravity was behind that point.
In other words, if we’re standing still and balanced, the center of pressure and line of gravity will be aligned—they have to be or instead of being balanced, we’d be falling forward or backward. However, if we’re moving quickly enough, the center of pressure and line of gravity can diverge, just like they did in the backward jump. In the pulls of the snatch and clean, where the pressure is on the foot in the top of the pull (balls of the foot) is not necessarily the point we’re balanced over. We can do what we did with the backward jump and direct our center of mass separately from the center of pressure (or, more accurately, keep it in the same place as the pressure shifts forward on the foot).
The Pull
In the top of the pull of the snatch or clean, lifters will be extended onto the balls of the foot to various degrees, but in virtually every case, the heels will not be in contact with the floor. This has been misinterpreted many times as meaning that the lifter’s balance (LoG) has shifted forward to the balls of the feet, and is therefore a mistake. However, if the pull is performed properly, the lifter’s balance will remain in exactly same place over the foot as the ankle extends—a little behind mid-foot—so that the system’s center of mass remains in the same place.
It should be very clear from this photo that the combined mass of the barbell and body are not centered directly over the balls of the foot, but a point farther back.
That is, as the lifter moves from the starting position into extension and back down into the receiving position, the combined mass of the bar and body, despite seeming to move all over the place, are always still balanced over the same place (at least on average). We know this is true if a lifter lands in the same place he/she began and is balanced when receiving the bar (we know this is not true if that lifter instead lands in front of or behind the place in which he/she started, or is unbalanced when receiving the bar, i.e. falling over).
(This can get confusing in the case of a backward movement of the feet without an equal backward movement of the rest of the system—see this article for more on that issue.)
Let Nature Take Its Course
What I’m about to say may seem to make no sense after I just spent 4 million words explaining this all—let this happen naturally. The idea here is to understand conceptually that feeling the pressure on the balls of your foot does not necessarily mean your center of mass has shifted over that point, which we would not want in a snatch or clean, and then to trust the body’s process of extending to produce force.
In other words, your job in the pull should be comprised of two simple tasks: staying balanced over the same place (line of gravity slightly behind mid-foot) and producing as much force as possible against the ground.
In the moment you separate the bar from the floor, you’ll likely feel the pressure on the foot slightly more toward the balls of the foot than the heels because the bar will be starting approximately over the balls of the foot and represents a significant chunk of the combined mass. You’ll quickly shift back slightly as the bar moves toward the knees to establish the balance over the whole foot that we then want to maintain throughout the lift—this again will mean the LoG is slightly behind mid-foot, meaning you’ll feel pressure on both the balls of the foot and heel, and may feel very slightly more pressure on the heel. As you finish the extension, the pressure on the foot will shift forward quickly to the balls of the foot exclusively—not because you and the bar are moving forward, but simply because the heel is rising off the floor.
If you simply focus on preserving the balance over the whole foot and driving straight up with the legs, this process will essentially handle itself. If you find yourself jumping forward or backward, you know your balance is shifting rather than staying in the same place.
