Should I worry about running damaging my knees?

Is it true that pounding the pavement causes arthritis? Does it matter what kind of shoes you wear or what surface you run on? When you run, every step you take can land with a force equal to almost four times your body weight. Run a mile, and you’re taking 1,500 steps like that. Sure, we’re all born to run, and perhaps even evolutionarily adapted to chase skittish deer across miles of open plain. But our ancestors weren’t running on concrete and the average hunter was probably