So just recently after doing sprints on the track (distance runner here) I had this pain in the side of my foot right under the ankle bone. This occured a couple of hours after the workout and now its a day after and nothing has improved. It was the first sprint workout of the year. It hurts when i pull my foot inwards sideways or when i stand on it and apply pressure. I have flat feet and was wondering if that may be the problem. My shoes are not new but i do not believe they are already worn out. I've never had anything like this before and I am worried. Any advice on how to treat it or what it is would be great. Thanks.