Foot strike patterns and collision forces in habitually.pdfVIP

Vol 463 | 28 January 2010 | doi:10.1038/nature08723 LETTERS Foot strike patterns and collision forces in habitually barefoot versus shod runners 1 1,2 3 1 4 Daniel E. Lieberman , Madhusudhan Venkadesan *, William A. Werbel *, Adam I. Daoud *, Susan D’Andrea , Irene S. Davis5, Robert Ojiambo Mang’Eni6,7 Yannis Pitsiladis6,7 1 Humans have engaged in endurance running for millions of years , transient, Mbody is the body mass, vcom is the vertical speed of the but the modern running shoe was not invented until the 1970s. For centre of mass, vfoot is the vertical speed of the foot just before impact most of human evolutionary history, runners were either barefoot and g is the acceleration due to gravity at the Earth’s surface. or wore minimal footwear such as sandals or moccasins with smal- Impact transients associated with RFS running are sudden forces ler heels and little cushioning relative to modern running shoes. with high rates and magnitudes of loading that travel rapidly up the We wondered how runners coped with the impact caused by the body and thus may contribute to the high incidence of running- foot colliding with the ground before the invention of the modern related injuries, especially tibial stress fractures and plantar shoe. Here we show that habitually barefoot endurance runners fasciitis6–8. Modern running shoes are designed to make RFS running often land on the fore-foot