Rolling the bar on deadlifts....

[Kiknskreem]

What are your thoughts on this Rip?

Someone recently made the point of an object in motion wanting to stay in motion, and that even momentum in the horizontal plain can then be directed vertically.... as in the kipping pullup.

[Mark Rippetoe]

Changing the direction of motion requires force, in the same way that changing the velocity requires force. This change during a kipping pullup is assisted by the stretch reflex inherent in the eccentric component of the down-stroke. But there is no down stroke in a deadlift. If you roll the bar toward you at the start of a pull from the floor, you are 1.) introducing a horizontal motion component that will have to be dampened before the vertical bar path can be expressed, and we do in fact want the bar to go up, and 2.) pulling from a position where the skeleton cannot transfer force optimally to the bar.

[XTrainer]

Even if this did work, it seems like a trick to deadlift more weight...not get stronger through deadlifting.

[George Noble]

But what about the first rep of a set of kipping pullups? That isn't assisted by a stretch reflex, but the horizontal movement still makes it easier. Right? And surely if you're well practised at deadlifting in this way, you'll be able to do it without ending up out of position, like the example of Andy Bolton bringing his hips down to the start position quickly.

[Mark Rippetoe]

A bodyweight exercise and a 1003 deadlift are not equivalent activities in terms of their use of a bodyweight-only stretch reflex.

[George Noble]

I know, and I wasn't comparing the two.

My first point was that the horizontal movement in a kipping pullup is not coupled with a stretch reflex when it is done on the first rep of a set, yet it still makes the pullup easier. Can this not apply to the deadlift?

My point about Andy Bolton was in reference to
"2.) pulling from a position where the skeleton cannot transfer force optimally to the bar."
But if someone is really well practised at this, then wouldn't they be able to roll the bar back and pull it from the correct start position? The comparison to Andy was from this quote in a different thread, where you said that well practised people can get away with doing stuff that would pull most lifters out of position.
"Notorious: The slight advantage it might confer is eaten up by the disadvantage of getting the bar out of position into a place where the pull off the floor is harder. If you drop your ass -- unless you're good at it like Andy -- you'll shove the bar forward, and then it has to be pulled back in as it leaves the floor. Straight lines make better bar paths."
http://www.strengthmill.net/forum/sh...25&postcount=5

[elVarouza]

I notice Magnusson rolls the bar toward him before he starts his pull. I don't get the point though, because strictly horizontal movement does not translate into upward movement. Maybe the bar gets slight upward momentum upon hitting the legs, but who knows.

What is it that Bolton does anyway? Is he trying to get a stretch reflex out of bringing his hips up and down quickly like that?

[SkinnyWimp]

Newton pretty much nailed this one a few hundred years ago. It is impossible to make something move up by applying only a sideways force to it. The corollary is that when applying only a sideways force to something, it won't move upwards. This doesn't even require gravity to be true.

[Mark Rippetoe]

Rolling the bar back in to the mid-foot before the bar leaves the ground is indeed what most lifters do. It can be done, albeit with less exact reproducibility than without the roll. My point is that horizontal movement is not useful in terms of making the bar go up, and that since the bar is going to leave the ground most efficiently from a position where the bar is directly over the mid-foot and directly under the scapulas, why not just put it there to begin with and call that the starting position?

[Patrick]

It's a comfort thing rather than a physics things. Tiger Woods places his feet and wiggles his ass a dozen times before he hits his drive and that's pretty much all you need to know. The optimum deadlift starts with a vertical pull. However, because humans are not machines, sometimes the feel you get from a good controlled roll is used get a good pull going. You feel the right stretches, the right symmetry, the right grip, and so on. I'd rather see a guy bob up and down into and out of DL start position with a static bar to get the same effect but the roll seems more common for whatever reason, probably because it involved movement both of the lifter and of the bar.

There shouldn't be ANY controversy that the physics makes pulling a rolling bar harder. Getting to the bottom of why it might be so common despite that is useful, and I think that's what I've tried to get at above.