Is Workload Associated With Internal Impingement in Professional Baseball Pitchers? An Analysis of Days of Rest, Innings Pitched, and Batters Faced

Background: Internal impingement is a common cause of shoulder pain and dysfunction in baseball pitchers. Purpose/Hypothesis: The purpose this study was to determine if the amount rest days between outings, number innings pitched each outing, batters faced outing are risk factors for internal professional It hypothesized that higher workload would significantly increase pitcher’s developing impingement. Study Design: Case-control study; Level evidence, 3. Methods: All (Major Minor League) pitchers who were diagnosed with 2011 2017 identified using Major League Baseball’s Health Injury Tracking System. A separate player usage data set used workload. authors compared variables (days rest, pitched, per game) 4 injury-exposure groups (pitchers documented <2, <6, <12, >12 weeks after control group no Student t tests or Mann-Whitney U tests. In within-pitcher paired analysis injury groups, during 3 acute periods (<2, <12 preinjury) baseline values (>12 preinjury). Results: Overall, there 624 period. Compared pitcher games (n = 213,964), all had more game ( P ≤ .003 all) < .001 all). There starting when controls However, comparing workloads impingement, significant differences faced, rest. Conclusion: This revealed greater percentage players healthy controls. did not seem be associated an