Please Scroll Down to See Forums Below 
top of your foot is likely not tendonitis, it may be a stress fracture, it is the classic place for one. It could be a tendonitis from a muscle that runs down the front, lateral aspect of your shin and then down the top lateral aspect fo the first one-third to one-half of your foot...did you start running, or sprint one particular time that you recall....alot of runners get this and call it "shin splints" and it can really extend onto the top of your foot like that. It could be new shoes you are wearing...you'd likely need to get some with more "arch support" which is the underside and medial aspect of your foot. Something as simple as that can certainly affect the tendons on the top of your foot. you'd be surprised.
