A mother presents with her 4-year-old daughter, Emma, with concern of left arm or shoulder pain. She denies any history of injury or trauma, but noticed Emma seems to be protecting her left arm and won’t extend it. This started after Emma was playing outside with her teenage brother, who built an obstacle course and was pulling Emma by her arms over the larger obstacles. On exam, Emma is holding her left arm with her other hand and resists any movement of her elbow, wrist, or fingers. She seems anxious. There is no erythema, warmth, edema, or signs of injury with tenderness over the radial head. What is the most likely diagnosis? Salter-Harris fracture Left clavicle fracture Nursemaid’s elbow Osteomyelitis