Abstract
ABSTRACT: Arm injuries are the most common throwing injury, with growing concern as the most severe injuries, such as UCL reconstruction, continue to rise. Furthermore, throwing injuries are frequently recurrent, suggesting once injured, players are at increased risk for another arm injury. The increase in injury rates and severity has been attributed to increases in pitching volume and year-round participation, and specialized training. Thus, initial efforts to prevent arm injuries by USA Baseball and Little League have focused on the extrinsic factor of pitching exposure in the form of pitch counts, yet arm injury rates have stayed constant. Therefore, injury prevention strategies should include extrinsic factors and address modifiable, intrinsic factors that are associated with arm injury. Collectively addressing factors, such as shoulder range of motion and strength deficits, trunk and lower extremity function, and implantation of training programs yields a comprehensive approach to reduce arm injury rates. We will use a directed acyclic graph (DAG) to organize how the internal factors (i.e., fatigue, injury history, range of motion, and strength) interact with the external factors (i.e., training load and pitching exposure) and how together they are thought contribute to potential injury and inform arm injury reduction strategies. This will provide a roadmap to build adaptable arm injury reduction strategies to improve the modifiable physical factors in context of the external factors that change over time and between throwing athletes. LEVEL OF EVIDENCE: Level V, expert opinion.