"Dr. Weyand gave two back-to-back presentations. The first presentation provided coaches with scientific insights on the mechanics of running speed. His second presentation provided the history as well as the current implications relative to the speed regression algorithm he developed with Dr. Matt Bundle of the University of Wyoming.
“I was really surprised that coaches understood that declines in speed were related to forces and not fuel supplies,” noted Weyand. “This suggests as complex as the details of motor control, force production and delivery are during sprinting, coaches are grasping the simple, informative and valuable take-home message that speed is all about hitting the ground hard and fast.”
Clearly the amount of time on the ground is minimal. It should be noted that from the half-way point of the stance phase to toe off force drops off dramatically.
wouldn’t the follow up to that be along the lies of…but this shouldn’t be a conscious effort and ground contact is representative of a number of factors.
Its like saying golf coaches agree the key to long straight drives is the clubface being square at impact and moving fast. Yes, but there are a whole lot of other bits that go with it and allow that to happen.
IMHO one of the best analogies Charlie gave was trying to spin a wheel with your hand, to make it go fast you skim it, if you consciously try and push it hard then it goes slower.
“It should be noted that from the half-way point of the stance phase to toe off force drops off dramatically. Therefore, push-off does not exist.”
“coaches are grasping the simple, informative and valuable take-home message that speed is all about hitting the ground hard and fast”
Few thoughts:
The data presented is only the vertical component of force. So it should be rephrased as: “it should be noted that from the half-way point of the stance phase, the toe off VERTICAL FORCE drops off dramatically”. If you look at typical horizontal force recordings, you can see that horizontal force increases dramatically in that phase of the stance. Since the vertical component is not nihil and the horizontal is increasing, the resultant force is well measurable and has effects, so yes push-off does exists.
The study was done on a treadmill, basically the grounds is going away from you so the push-off phase is actually unecessary for locomotion.
The guy on the video has terrible running form and is obviously not a sprinter.
Those were the first things I noticed too. While I don’t know how much different it makes for the studies, it seems that there are a lot of studies done on treadmills with non-sprinters. This automatically makes me question the validity of the results for sprinting over the ground.