Changes in the step width, step length and step frequency of the
World's top sprinters during the 100 meters
by Akira Ito
excerpts from the paper‚..
The stride patterns of 18 male sprinters taking part in the first round heats of the 100m at the 2005 IAAF World Championships in Athletics were analyzed. It was found that the main difference between sprinters at the 10.12 - 10.32 level and sprinters at the 10.40 - 10.90 level was in the step length. It was also found that both groups decreased their step width from 0.39 +/- 0.07m in the first step after the start to 0.17 +/- 0.04m in full stride running. The authors suggested that a wide step width (increasing step width) may be best suited for developing driving force during the long foot contacts in the acceleration phase while a narrow step width may be best for the short foot contacts of full stride sprinting.
To me this speaks very clearly to the Approach Run set-up, in that the vaulter "drives" from the first step and continues to accelerate into "full stride sprinting" to a "MID" that is 6 steps from the takeoff. From the "MID" the vaulter, like the sprinter at full stride sprinting, will try to "get the feet down" and achieve the "narrow step width which may be best for the short foot contacts of full stride sprinting and I may add‚. a functional left-right-left "impulse" at takeoff.
I have studied step lengths in vaulters, long jumpers and triple jumpers for 40 years now. The last 2/3 steps just before the "MID" are always longer (if the jumpers approach run is correct and dynamic) than the average steps from the "MID" to the takeoff. I don't have a percentage yet but could collect that if the vaulters on PVP wanted to give me the distance from the start of their approach to a 6 step "MID".
For example my full 6 left/12 step approach is 63 feet, my "MID" is 38. I cover 25 feet from the start to the "MID". I know that my last step before the "MID" is 5'1". My steps from the "MID" to takeoff are 4'11" each‚ except the penultimate of course. If someone wants to do the math % of decrease from 5'1 to 4'11 we might come up with a formula that would fit everyone including world class
Paper Results and Discussion
As expected, the step length increased gradually during the early part of the acceleration phase. The patterns of increase were similar in both groups. However, the better group had a longer step length during this acceleration phase. The same was true for full stride length, which was, on the average, 0.12 +/- 0.03m, longer in the fastest group.
The step frequency was maintained at almost the same level (4.56 +/- 0.16 steps/s: in the acceleration and full stride phases and no difference was observed between the groups.
So what have we just been told?
First faster sprinters/jumpers will have longer step lengths.. Number two, faster vaulters can hold higher.
Revisit my chart.. It is proportional...
A third, and a very important, point that needs to be made and is where this post is headed. Is this..
The first part of the approach is just as important as any part of the vault. That/this is why the way you "toe" the mark, hold the pole and "come out of the back" has to be performed in a very balanced, natural and mechanically sound way.. Skips, pumps, gallops, etc are not correct.. the way petrov describes the start is the way to do it..
And my most important point for today‚‚..the beginning steps have to be "natural" not "over controlled" in an effort to save something for the end...... but accelerated and progressive.
In the heat of battle the athlete will go to a "natural" feel‚so train and practice natural acceleration. My chart gives you the correct step patterns for the grips and heights ‚ is there a +/- ? yes but it is minimal.
Start you're Approach with the takeoff foot toeing your "mark"‚ the other foot is a couple of feet behind the front foot.. just like a standing sprint start.
Hold the pole (right handed vaulter) right hand at the waist, left wrist high and straight out from the sternum‚ 8 to 10 inches.. hold the pole in the "forks" of the hand‚ left elbow down and below the left wrist. Push out/start like a standing sprint but maybe at 85/95%. "sprint to the "MID".. then think "turnover"‚. getting your feet down into what i call a "piston" action into the left-right-left plant rhythm.
Finally use my chart to setup and practice your run on the track.. coach job/ladyvolspvcoach has setup a routine from my chart that works.. ask him to share it..
Later.. have a great preseason.. now is the time to fix your run‚
dj
PS.. I would love to go to San Diego with all the vaulters there and present my thoughts and info on the approach run.. I think and I'm sure there would be something, over a 2/3 day time period, that each vaulter could get a positive result from..
If anyone close to the vaulters or USATF wants to put "a word out" to help me get that arranged I would be grateful.. sorry to "self promote" but that seems to be the only way to get heard. I'm available anytime they want to do a session.. this fall during the "off" season would be best‚.. Mike Tully and I started revamping his run 18 months prior to the 84' games.. it worked..
Come out of the back... Get your feet down... Plant big