Researchers from Penn State University found that the foot and ankle structure of sprinters is significantly different from that of a non-sprinter. The findings not only explain why some people are faster runners than others, but could also lead to new advancements for treatment for people with limited mobility and have difficulty walking.
The researchers studied two groups of eight males. The first group comprised males who were involved in regular sprint training and competition, with at least 3 years of continuous training. The second group comprised eight males of similar height to the first group who had no experience with sprint training or competition, according to a press release.
MRI scans of the right foot and ankle of each participant showed that the Achilles tendon lever arms of the sprinters were 12% shorter than those of the non-sprinters. They also found that the combined length of the bones in the big toes of the sprinters were an average of 6.2% longer than the non-sprinters. The first metatarsal was also 4.3% longer in the sprinters.
The scientists also developed a computer model to investigate the effect of the foot and ankle dimensions on muscle contributions to forward propulsion. They found that the shorter Achilles tendon and longer toe bones allow sprinters to generate greater contact force between the foot and the ground and maintain the force for a longer duration. These dimensions also allow the calf muscles to do more work, providing an advantage during the acceleration phase at the start of a sprint race.
“Our results may be useful in helping people who have difficulty walking, such as older adults and children with cerebral palsy. If we can better understand how the shapes of bones influence not only muscle leverage, but also the ability to move, it may be possible to surgically alter the foot bones of people who lack mobility to help them move better,” Stephen Piazza, associate professor of kinesiology, stated in the release. “The results even might lead to screening tools for the general population. An MRI could determine if you are at greater risk for loss of mobility. If so, you might be more motivated to maintain your ankle strength with a strength-training program.”
The study was published in the Proceedings of the Royal Society B.