It is commonly accepted that runners get injured at some point, and most accept this as an inevitable outcome of running. For some this becomes a cycle of running, injury, recovery, and running again.
Some people think running is something we are not designed to do. Other say the high physical demands placed on our bodies are the cause and thus are running too much. However, we are designed to run. Humans are the most perfecting designed endurance running machine on the planet. Other animals can run, and run faster, but humans can run further and for longer than anything else.