CT Support Force in Sprinting

[Ken Jakalski]

For those of you trying to visualize forces peaking in the first third of the stance phase during high speed running, the following video from SMU's locomotion lab should be helpful.

The tracings show that force has pretty much ended by the latter phase of stance, at the time when most believe there is a powerful and active "push-off."

And if you pause the clip, note how far the arm actually swing during the period when forces are at their peak.

Again, a lot of these issues just aren't intuitive. For example, many still believe that armswing is a key contributor to force on the ground, but you'll see that, during contact times of about nine hundreths of a second, that isn't the case.