Besides running, I am also an Elliptical Machine fanatic, and go about a hundred mph on the thing for an hour at a time, sometimes two.
I have developed arch pain in the area of the Posterior Tibial Tendon. I really don't know if it is related to the Elliptical machine, but was thinking that maybe on the downstroke, when the ankle is in an exagerrated "flexed" position, it may tend to pull that tendon away from it's attachment points on the arch (navicular bone).

Has anyone else experienced arch pain from using the Elliptical or Arc Trainer machines?