Abstract
A 14-year-old right-hand dominant female lacrosse player presented with a complaint of right shoulder and upper posterior thorax pain of 8 days' duration. She had been playing lacrosse at the attack wing and midfielder positions and experienced insidious pain after a game. She had no history of trauma to that shoulder during that game and had not experienced an injury in the past. Six days after the pain developed, she woke up one night with a sudden increase in the pain, which brought her to tears and caused slight difficulty with breathing. The pain was located anteriorly just lateral to the right sternoclavicular joint and posteriorly in the paraspinal muscles in the upper thoracic region. Physical examination suggested a first-rib stress fracture, which was subsequently confirmed by chest and shoulder radiographs.