Shin splints cause discomfort, pain or tenderness on the inner part of the lower leg. There may also be swelling of the lower leg or pain that is worsened during physical activity, according to WebMD.
Shin splints are caused by a variety of conditions, such as stress fractures in the lower leg or muscles that are overused, which leads to swelling or irritation. People with flat feet, also called overpronation, are susceptible to shin splints due to the extra pressure placed on the legs from a lack of arch. After treatment for shin splints, the pain goes away and flexibility and leg strength return to pre-injury levels.