Review Question - QID 213754

A 12-year-old boy presents to his primary care doctor with elbow pain. He states that he noticed it yesterday while at a sports camp. He has been unable to participate in many activities secondary to this pain. He thinks the pain started when he participated in a pull-up competition. He also recalls being in a tug of war competition, which may have contributed to his pain. He is otherwise healthy and takes no medications. His temperature is 99.0°F (37.2°C), blood pressure is 114/64 mmHg, pulse is 90/min, respirations are 19/min, and oxygen saturation is 99% on room air. Physical exam is notable for pain with supination of the wrist and joint tenderness over the lateral epicondyle. Which of the following is the most likely etiology of this patient's symptoms?