so i see video of carl lewis doing a block start and this video of asafa powell exiting the blocks. ive noticed that powells heel recovery on his first step is very low (toe scrapes ground), but carl’s heel almost touches his butt on its way through its first step. what are people’s thoughts on this? is one way more mechanically correct than the other or is really just an individual thing?
lewis -> http://www.youtube.com/watch?v=RwNw6zT2s-U&feature=player_embedded
I strongly believe that low heel recovery is more efficient. Carl was not a good starter. Powell is one of the best starters ever.
I agree, lower heel recovery in acceleration is ideal for most-it keeps you in a better push-like position.
Low heel on first step, drags toe on the second step.
very valid point, but is there any reason why it is more efficient? i mean, it looks like even in the first few steps having a shorter lever to swing would be easier, any biomechanical reasoning why having the leg stay somewhat straigter is beneficial to these steps?
A high step will likely result in too long of a first step causing the sprinter to become upright prematurely.
Keeping the first few steps low permits one to get the feet down fairly quickly and, as said previously, keep the strides more push-like with the feet remaining behind the torso moreso then with the higher, slower step. This helps to achieve a position that some coaches refer to as establishing/achieving positive shin angles.
In acceleration the forces you need to produce are horizontal and gradually transition to vertical force production as you near top speed.
suggest the focus is distance and the rear leg full extension is for that reason. If alternatively the focus was on leg speed (heel to butt, cycling) the step would be much earlier, no extension. It is shorter in a straight line. have a look at the boy in the vid I sent you, from the side it could be a white AP.
Carl’s start doesnt look all that explosive. He runs up out of the blocks. Asafa is a freak out of the blocks. There is something special about Asafa’s acceleration mechanics that I’ve never been able to identify. He has tremendous body angles and lean and steps down incredibly fluid. He exhibits this form even when doing 70% accels every time I’ve seen him. Can anyone help me identify this trait/cue? Its very noticeable in the 300m he ran. His acceleration mechanics are great.
Heel to butt is a fast lever, which diminishes the ground contact time and takes away from force production. Low recovery ensures full extension and longer ground contacts for force production.
As people have somewhat touched on, low heel recovery is more bio mechanically efficient as there is no wasted vertical movement. The first few steps are at low speeds which require much longer ground contact times in order to apply sufficient force for maximal acceleration. The direction of force being applied can be seen in the body angles during those steps. There is no need for the foot to come up then go back down, only to apply force in a different direction.
Try putting a harness on an athlete and have them try to drag you forward. If they have low heel recovery they will exert much more pull than if they cycle their legs as though they were in full stride. I do this with high school athletes so they can learn the feeling of the first few steps.
I don’t believe I’ve ever had to discuss heel recovery on initial acceleration with any athlete I’ve ever worked with. If you do, something is terribly wrong.
I personally don’t like to look at that clip of Asafa from blocks as he does that extremely slow for the purpose of the advert. Low heel recovery for the accel phase. Watch clips of Ato Boldon,Asafa (race clips),Bolt (lots of head on clips available),Michael Frater etc. These guys display great low heel mechanics.
haha, any idea what could be horribly wrong with me? my heel recovery has gotten lower, but i had to work at it fro some reason. my natural reaction was always to overstride and i had heel recovery that went firther up than lewis’s 
good point, just it was the first video i remembered where it is very easy to see his toe scrape
makes sense, ive never thought of it as wanting to extend the time the stride should take (only if more force is being applied of course)
How does heel to butt become any faster a lever than heel 200mm from butt. It is not until the heel becomes further away from the butt than the distance from knee to ball join in hip does the lever become distorted.
in the videos it looks like lewis’s step path makes the foot easier to pull through than powells because the foot is closer to the hip joint while passing under the body
Lewis heel to butt at start, notice how he almost stands up instantaniously, if he stay low like Powell and used the same mechanics ??? it wouldn’t be pretty.
Number 2, I am really curious as to what cue one would use to get an athlete to use low heel recovery without scrambling his brain (and start)?
I’m a tall guy and could see how this style could be effective for taller athletes.
T
It would be nice if anyone (including) number 2 could share video or their athletes making change. Unless it’s just falling into place over time, I would like to see video of changes from any means be it cues or specific training.
Think drag the toe. You Won’t drag it usually hut you will get low heel recovery.