Scientists Analyze Some of the Fastest Human Sprinters in the World: The Key to Speed

Olympic-level sprinters are the fastest humans on the planet. Now, scientists have taken a closer look at their unique gait features that allow them to move so quickly. It turns out that the secret to super speeds lies in the distinct limb dynamics that sprinters use to elevate ground forces upon foot-ground impact.

Previous studies have shown that faster runners attain faster speeds by hitting the ground harder with their feet in relation to their body weight. Yet how faster runners managed to do this was a mystery-at least until now.

"Our new studies show that these elite sprinters don't use their legs to just bounce off the ground as most other runners do," said Ken Clark, lead author of the new paper, in a news release. "The top sprinters have developed a wind-up and delivery mechanism to augment impact forces. Other runners do not do so."

The distinctive gait features occur as the lower limb approaches and impacts the ground. Essentially, the fastest athletes cock the knee high before driving the foot into the ground while maintaining a stiff ankle. These actions elevate ground forces by stopping the lower leg abruptly upon impact. In fact, the fastest runners decelerate their foot and ankle in just over two-hundredths of a second after contact with the ground.

"We looked at running speeds ranging from 3 to 11 meters per second," said Clark. "Earlier studies in the field of biomechanics have examined ground reaction force patterns, but focused primarily on jogging speeds between 3 and 5 meters per second. The differences we found became identifiable largely because of the broad range of speeds we examined and the caliber of the sprinters who participated in the study."

The findings reveal a bit more about how some people can run so quickly. In fact, it reveals that the classic spring model, which scientists have used to describe sprinters in the past, is not sufficient for understanding the mechanical basis for sprint running performance.

"This provides scientific information so coaches and athletes can fully identify what to train," said Clark. "It is our hope that our results can translate into advances in evidence-based approaches to training speed."

The findings are published in the Journal of Experimental Biology.

Want to see the runners for yourself? Check out the video below, courtesy of YouTube.