It doesn't have many rules, it doesn't take much teamwork, and it requires little in the way of equipment, training and talent. Almost anybody with two legs and a healthy heart can run, almost anytime and almost anywhere. There is, of course, a yawning chasm between recreational joggers who log a few miles after work and the cabal of athletes who win marathons and Olympic medals. Most people can't imagine running without them. Casual athletes wear running shoes to protect against injury by cushioning impact and aiding joint alignment.
Serious runners count on their shoes to improve their performance as well.
After decades of investigation and millions of dollars of investment, the running shoe is still very much a work in progress. In fact, its brief history can be seen as an ongoing experiment in biomechanics, materials and design. Elite runners' quest for better fit, better protection and better times has driven a technological renaissance that has reached far beyond the track. Meanwhile all the brainpower and high-tech analysis brought to bear on the running shoe in recent years have been toppling some cherished assumptions. The roles of impact and alignment in running injuries and athletic performance turn out to be more subtle and complex than anyone expected.