You might only be due for a medial forefoot wedge (like are built into Specialized Body Geometry shoes, or you can have put into your shoes at a shoe repair shop).
If your forefoot doesn't get the weight transfer pattern heel-toe like it does when walking, it doesn't always get set up to be a rigid lever. So it kind of collapses (pronates) throwing your foot/ankle/knee/and sometimes hip out of whack. Sometimes the poor achilles tendon will jump in at this point and try to stabilize the system. Since it really can't do that well, ya get tendonitis and other nasty boogers. (if the achilles doesn't even try, you can end up with knee pain as it is the next joint to take the stress)
A medial wedge (3 to 5 degrees) in the forefoot stabilizes and approximates a rigid lever.
Most PTs can give you a wedge of the correct angle for you, for free (billed as part of your treatment) A shoe store or shoe repair shop will charge you about $15. Bike shops sometimes do it as part of a fitting.
If you want UNOFFICIAL NOT-MEDICAL-ADVICE DO AT YOUR OWN RISK hints of how to fake a wedge with a piece of typing paper, PM me.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson