When I run my left shin is stiffening up, feels like it s burning, and there is a spot approximately 3 inches above the ankle bone on the muscle that is visibly inflamed appearing as a lump about thumb size which fades after 20 minutes or so. This seems to focus on the muscle not the bone and only on the left side. Is this cause for concern or something that can be cured with ice, heat, and rest? Oh, it happens on brisk sustained walking to