CHAPTER 20: FORCES


ACTIVITY 3: COMPREHENSION 1 Read this article and answer the questions that follow.


Running without shoes softens the blow


To complete a recent study, a team of scientists left Boston and went halfway around the world, to the middle of Kenya. They wanted to find out more about barefoot running.


Sure, people can run barefoot anywhere. But the Rift Valley Province in Kenya has produced some of the most famous long-distance runners in history, and many of these athletes grew up not wearing shoes. With a video camera in hand, scientist Daniel Lieberman and his colleagues visited some of these runners to figure out what a difference shoes make.


When a bare foot hits the ground, the blow is softer and the running motion smoother. This research suggests that running barefoot may have advantages over running with shoes on, though more studies are needed to determine whether or not barefoot running reduces the chance of injuries. Also, the team didn’t investigate whether there’s a difference for sprinting.


Previous studies have shown that when a person runs barefoot, she lands on the fronts or middles of the feet. Then the heel goes down. During this process, the weight of the body is at first on the front of the feet, then moves to the heel. Lieberman and his colleagues saw this motion firsthand in Kenya — the runners landed on the fronts of their feet.


When a person wears shoes, however, he tends to run so that his heels hit the ground first. The impact of the heel hitting the ground may be much more forceful than the impact of the front of the foot hitting the ground.


‘A rear-foot strike is like someone hitting you on the foot with a hammer with about one and a half to three times your body weight. It would hurt without a shoe,’ Lieberman told Science News. ‘A forefoot strike is like having no one hit you at all.’


Adapted from: www.sciencenewsforstudents.org a. Name one benefit the researchers found for running barefoot.


b. What does the article say the team did not investigate in this study?


c. Describe the difference in how the foot lands on the ground when running barefoot compared to running in shoes.


d. What does the researcher compare a rear-foot strike to if running shoes are not worn?


UNIT 5: MOVEMENT


97


PHYSICAL WORLD


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