SS:BBT3 Excerpt : Pulling Mechanics, 2

[stef]

This is the second part of an excerpt from the Deadlift chapter of Starting Strength: Basic Barbell Training, 3rd Edition, available for sale now (http://aasgaardco.com/store/store.php?crn=199&rn=413&action=show_detail). It deals with the non-vertical arm angle and the biomechanics of the position. This explanation is based on consultations with Dr. Dennis Carter at Stanford University and other mechanical engineers, and is not available anywhere else in the literature.

Article (http://startingstrength.com/index.php/site/ssbbt3_pulling_mechanics_2)

Resources Page (http://startingstrength.com/index.php/site/resources)

[Mac Ward]

Rip,

Read it twice, never, ever thought about "why" it was important the arms hang 7-10 degrees off of plumb, just figured it was because the shoulders were supposed to be forward of the bar because...you said so...and that put the bar under the middle of the scapula - where you told me we are best able to lift. Through observation, it is indeed obvious that the bar (if heavy enough) will hang from that position. Having an understanding of how the lats attach to the humerus and the role they play - brings it all together.

Perhaps it is further explained in the full text (in which case I will gladly wait for our copy to arrive) but I have a question.

You mentioned in the article that if the hips are too low the angle of the attachment of the lats to the humerus is < 90 and if hips are too high, the angle is > 90. You also stated that that when the hips are too low, they will rise to accomodate the angle (meaning, get that attachment angle to 90). I also took away that if the hips are too high, the bar will be in front of the ideal posiiton of centered below the scapulae, and a second moment arm is created with the foot (that part was tough to visualize, but I got it...) I am assuming this is why the bar is often in front of the mid foot - though not entirely sure this is the case.

If the back is properly held in isometric contraction and neutral, the length of the back becomes a constant, so barring growth or change in height for a given lifter, the height of the hips should always be the same for that lifter. Given the anthropometic differences in lifters, how "high" the hips are differs between lifters, but the hips should be at a height that puts the lats at a 90 degree attachment to the humerous.

How do we find that "perfect" position? I struggle with the deadlift, the bar always drifts out in front of me, and every once in while I feel strong, the lift feels short and I wonder why I am so weak on other days. From this article I can deduce two things. Either my lats are not doing their part, or I'm set up wrong.

I have done my best to follow the setup routine you have on the wall at WFAC, approach the bar, shins nearly touching, bend down without bending knees, grab bar, bend knees until shins touch the bar, raise my hips (higher than I think they should be), squeeze my chest up - until the bar comes off the floor.

Thanks in advance for all of this. I truly appreciate it. If I missed something or need to read something else...direct me, and I'm on it.

Mac

[Good Ryan]

I have done my best to follow the setup routine you have on the wall at WFAC, approach the bar, shins nearly touching, bend down without bending knees, grab bar, bend knees until shins touch the bar, raise my hips (higher than I think they should be), squeeze my chest up - until the bar comes off the floor.


Moving the shins to the bar and then stopping when contact is made sets the level of the hips, assuming you started with the bar 1 inch from your shins and over the middle of the foot. If you move your shins into the bar, and then raise your hips, then you have moved the hips higher than they should be. If you raise the hips and pull the bar back into the more verticalized shins, then the bar is behind the middle of the foot and is perhaps why the bar is moving forward on you.

[Mark Rippetoe]

How do we find that "perfect" position? I struggle with the deadlift, the bar always drifts out in front of me, and every once in while I feel strong, the lift feels short and I wonder why I am so weak on other days. From this article I can deduce two things. Either my lats are not doing their part, or I'm set up wrong.

If the correct back angle has been established, the lats et al are at 90 degrees to the humerus and the back angle that produces this relationship will be stable as the bar leaves the floor. The correct position is determined by the bar in contact with the shins over the mid-foot, the back angle that results from chest squeezed up into thoracic and lumbar extension, and the load of the lifter/barbell system balanced over mid-foot as the bar is pushed away from the floor.

[veryhrm]

Coach,

Two issues come up for me when when reading these new pulling excerpts:

1) I seem to have lost the main thread of the argument: what parameter is actually being optimized for in this discussion ? My impression after a few readings is that it would be the most weight that can be lifted per calorie expended or something like that. The efficiency analysis would make a lot of sense for running or cycling since those sports are in many ways limited by energy production over time over many reps, but if we're talking about maximal or near maximal efforts is it the same thing ? I think all sorts of inefficiencies in energy expenditure would be allowed or desired if they resulted in a bigger lift. How about when using it as an exercise to become strong? (presumably for sport, yard work and death resistance).

2) A specific example/question: is the strength of the lats the limiting factor in the DL ? If not, why would minimizing the force they apply matter? ( force F in Figure 4-25 ) That is, if the lats could pull at 95% intensity at an inefficient 65 deg. vs 86% intensity at 90 deg but this would allow for better use of glutes or quads or whatever so i could lift more wouldn't that actually be preferable ?

(i've never lifted in competition, am not a coach and only have lifted 335lbs for 5 as training/exercise (at 6' 258lbs and 30+ % bf), so i'm not arguing from personal expertise here, just based on the text)

[Mac Ward]

If you raise the hips and pull the bar back into the more verticalized shins, then the bar is behind the middle of the foot and is perhaps why the bar is moving forward on you.

Ryan, thanks for the response...bar never moves during setup, and I start with shins about 1 inch out. Sometimes I get it, sometimes not so much.


and the load of the lifter/barbell system balanced over mid-foot as the bar is pushed away from the floor.

And that's the part I'm always searching for...I look forward to having eyes on again in Atlanta.

Thanks for taking the time.

[Mark Rippetoe]

1) I seem to have lost the main thread of the argument: what parameter is actually being optimized for in this discussion ? My impression after a few readings is that it would be the most weight that can be lifted per calorie expended or something like that. The efficiency analysis would make a lot of sense for running or cycling since those sports are in many ways limited by energy production over time over many reps, but if we're talking about maximal or near maximal efforts is it the same thing ? I think all sorts of inefficiencies in energy expenditure would be allowed or desired if they resulted in a bigger lift. How about when using it as an exercise to become strong? (presumably for sport, yard work and death resistance).

The main thread of the argument is not being presented here, since this is an excerpt of a book chapter. This: I think all sorts of inefficiencies in energy expenditure would be allowed or desired if they resulted in a bigger lift. is a restatement of the argument used by the proponents of the curved bar path in the Olympic lifts. Once again, please list a specific instance of an inefficiency in energy expenditure resulting in a heavier weight being lifted.


2) A specific example/question: is the strength of the lats the limiting factor in the DL ? If not, why would minimizing the force they apply matter? ( force F in Figure 4-25 ) That is, if the lats could pull at 95% intensity at an inefficient 65 deg. vs 86% intensity at 90 deg but this would allow for better use of glutes or quads or whatever so i could lift more wouldn't that actually be preferable ?

The ability of the body to keep the bar over mid-foot is one of the factors determining 1RM deadlift. Minimizing the force the lats apply and maximizing their force application efficiency are two different things. The more efficiently the lat exerts its control over the humerus, the more force available to control the bar position over the mid-foot. If the lats fail to control this position due to an inefficient angle of attack on the humerus, the bar path will not be vertical. Gravity acts in one direction, and work against gravity occurs in one direction: vertical. So the bar path must be controlled, and the glutes, hamstrings, and quads are perfectly capable of adjusting the pull to make a vertical bar path. So they should. When they do, you'll be using them the best way you can.

[Jonathon Sullivan]

I must be missing something. In any pull the work to get the bar from floor to lockout or clean/snatch rack is done in a vertical direction. The minimum force necessary to get the work done will therefore be applied in a strictly vertical direction. Any force avoidably expended in a non-vertical direction is wasted. Wasted force does not contribute to the lift. If the lift is at the limits of the athlete's ability, wasting force can make the difference between completing the lift and missing the lift. And while I am not nor will I ever be a competitive weightlifter, everything I've learned so far indicates strongly to me that making the lift is for some reason considered preferable to missing the lift. At least the Chinese and the Bulgarians seem to think so.

Moreover, since it is clear that doing a clean or snatch with a bar path that comes damn close to completely vertical (especially in the first pull) can and actually has been done...

http://www.youtube.com/watch?v=6TlbDQUWs0s
http://www.youtube.com/watch?v=9LLbOsKkofc&t=267

...without causing proton decay or implosion of the spacetime continuum, we must conclude that there are no strange, occult, chaotic, non-greedy algorithm-determined forces or gremlins at play that make a non-vertical bar bath mysteriously necessary. At all. In other words, you can do a snatch without wasting work moving it in a non-vertical direction. So why wouldn't you?

All of which is so elementary I'm actually embarrassed to type it. Maybe I'm just dull. I like to fight as much as the next guy, but I don't see why this is an argument. Book color? Okay, maybe we can fight about that, I guess. But this is just...physics.

[HiTekLuddite]

Very nice work! I ordered my copy and some other stuff. Merry (early) Christmas to me!!