geoffwnz:
Yes there is a higher impact load when running but by and large it seems to have been disproven that running "causes" knee issues. Any knee issues I have have from running and training for ultra marathons have turned out to be stability issues in the various supporting muscle groups that you can train. Hip instability for example causing knee pain. Solution, improve the strength and stability training.
About two years ago I got some significant pain in one of my knees, which is only my second injury in over 20 years of running. It turned out that my shoes had over 1200km of mileage on them - well in excess of the 500 to 800km recommendation. I swapped them out for a new pair of comfort orientated running shoes, the pain abated over a few months, and then I moved back to performance shoes (another new pair, obviously).
I wonder how many people with knee complaints are unaware of how frequently running shoes need to be replaced.
