More importantly, as the figure shows, the force generated during the last fifteen percent of ground contact is minimal at best (about 100 newtons or 20 pounds). The best sprinters discovered that, if they ended this unproductive portion of ground contact early, they could get back to productive side of the activity (front side) sooner.
– Ralph Mann
What I like about the charts on page 135-137 is that they mix the actual kinematic and kinetic data with the sprinters are able to do as athletes. No matter what the debate is on with physics, the athlete is the center and focus of what we are trying to improve. What the athlete can feel, and, what they can actual control, is more of the art of coaching. While the charts are useful to see, forces over time that is, the curves and slopes are highly dependent on stiffness and joint function. I hope the Podium Project will focus on foot strike more in order to properly capture what is happing within the context of ground contact.