extensor tendinitis

The top of my foot hurt after my trail run on Sunday, but I've felt it before so just blew it off. Trail running really works different muscles so figured that I just twisted it weird on a rock. That probably is what happened, but had a great run yesterday on TL after which it hurt to walk. Strange it didn't hurt running just walking. Well it's not debilitating just annoying. I guess you just have to "take the good and take the bad, there you have the facts of life." I plan on swimming and biking the next two days to lay off of it some.