Abstract

Baseball pitching involves the fastest recorded movement of a human body segment, with the upper extremity rotating around the glenohumeral joint at a rate of over 7,000°/second. On average, roughly 116,000 shoulder injuries are sustained by high school athletes each year. Of these, approximately 39% are musculoskeletal strains and sprains. Multiple risk factors have been explored when studying elbow and shoulder injuries in pitchers. These factors include, but are not limited to, the number of pitches thrown during a season, fatigue, height, and mass. Although steps have been taken to mandate rest days and maximum pitch counts, elbow and shoulder injuries continue to increase among pitchers. This indicates that there may be other factors leading to elbow and shoulder injuries in pitchers besides the in-game workload. As such, means of better quantifying motions during practice and competition are valuable for reducing the risks to pitchers’ elbows and shoulders. Wearable Inertial Measurement Units (IMUs) record lower measurements compared to marker-based motion capture for assessing shoulder rotation speed, elbow varus torque, and arm slot when pitching. However, these devices have been shown to be reliable in their measurements. This reliability justifies IMUs’ place in clinical and research applications for describing the demands and workload of pitching. Nevertheless, coaches, clinicians, and researchers should be mindful that the measurements from currently available IMUs may be less accurate than marker-based motion capture.