We found no basis for increased intercompartmental pressure in either the anterior or posterior compartments as the cause of shin splints. The pain in all 14 of the patients studied was localized to the posterior medial border of the tibia at the origin of the posterior tibial muscle, and evidence of periostitis in this area was seen in two of our patients, suggesting the possible tearing away of the posterior tibial muscle from its origin. Shin splints is a lay term which has assumed medical diagnostic significance and should be removed from common usage by more accurately localizing the focus of pain.