Clinical Scenario: Shoulder range of motion (ROM) in throwing athletes relies on a balance of mobility and stability to maintain proper function and health that, if disrupted, can lead to shoulder injury. There have been several studies that address the relationship between ROM deficits and overhead injuries; however, it may be unclear to clinicians which interventions are most effective for increasing ROM in the glenohumeral joints of overhead athletes. Clinical Question: In overhead athletes who have deficient shoulder ROM, is instrument-assisted soft tissue mobilization (IASTM) more effective at acutely increasing ROM over the course of a patient’s treatment when compared with self-stretching? Summary of Key Findings: A thorough literature review yielded 3 studies relevant to the clinical question, and all 3 studies were included. Two articles found a significant increase in acute ROM when compared with a self-stretch measure. All 3 articles showed increases in internal rotation and horizontal adduction, and 1 study reported an increase in total arc of shoulder ROM. Clinical Bottom Line: There is moderate evidence to support the use of IASTM to acutely increase ROM in the glenohumeral joint of overhead athletes. Clinicians should be aware of the variability with recommended treatment times; however, positive results have been seen with treatments lasting 5 to 6 minutes per treatment region. There is no consensus for treatment intensity, and certain IASTM tools require certification. Strength of Recommendation: Grade B evidence exists that IASTM is more effective at increasing shoulder ROM (ie, internal rotation, horizontal adduction, external rotation, total arc of motion) in overhead athletes than self-stretching measures.