Hello Dr. Christensen, I run about 3-5 mile about every 2-3 days. I like running, but over the past year of running a further distant, have noticed a lump (half dollar in size) on my left outer shin muscle when running. It hurts to run and only appears when I run. I sticks out about 1/4 inch and sucks back in when I tilt my instep up and pushes out when I tilt instep down. It only hurts when running goes away after about 30 min. I do stretch before and after runs. My medical conditioning is rather good. Im very healthy for a 38 year old, but do suffer from Plantar fasciitis (about 10 years). I wear top of the line stabilty shoes for over pronation, and wear orthodic inserts with regular shoes and work boots. I only take high blood pressure medication (low dose losartan. My few questions are what could this possibly be? Should I stop running for now and go see a Sports Medicine Specialist or a Phisiospecialist or even just try my Primary Care Doctor? Respectfully, Chris