This study aims to use ultrasound imaging to assess the health of the ulnar collateral ligament (UCL) of the elbow, which acts as a major stabilizer in overhead throwing athletes and is often injured in baseball pitchers. The health of the UCL will be assessed by measured the amount of laxity in the UCL, identified as the distance between the end of the humerus (arm bone) where the UCL originates and the beginning of the ulna (forearm bone) where the UCL ends. An increase in this distance indicates an increase in laxity of the ligament, which is a risk factor for injury/tearing of the ligament with repetitive throwing seen in baseball pitchers. Measurements will be made at rest and under 3 pounds of valgus stress at 30 degrees of elbow flexion where the UCL acts as the main stabilizer of the elbow. Valgus stress is necessary for this procedure because damage to the ligament will be most clearly seen in this position when compared to the measurement at rest.