A physical therapist once told me that the number of runners (that is, people who have done it regularly for years) who have non-trivial knee problems is in the

A physical therapist once told me that the number of runners (that is, people who have done it regularly for years) who have non-trivial knee problems is in the neighborhood of 75%. Don’t know the source behind that, but it’s stuck with me. And the reason I was there was because of the knee problems I had from running.