https://www.selleckchem.com/products/fti-277-hcl.html 1; 95% confidence interval 1.2, 3.6; P less then .01). Athletes who returned to knee-strenuous sport before 9 months after reconstruction had a higher rate of second ACL injury (hazard ratio = 6.7; 95% confidence interval 2.6, 16.7; P less then .001). There was no association between symmetrical muscle function or quadriceps strength and second ACL injury. CONCLUSION Returning to knee-strenuous sport before 9 months after ACL reconstruction was associated with an approximately 7-fold increased rate of sustaining a second ACL injury. Achieving symmetrical muscle function or quadriceps strength was not associated with new ACL injury in young athletes. J Orthop Sports Phys Ther 2020;50(2)83-90. doi10.2519/jospt.2020.9071.OBJECTIVE To investigate the relationship between baseball participation and health (musculoskeletal, general, and psychological health) and to identify research gaps in the existing literature. DESIGN Systematic scoping review. LITERATURE SEARCH Medical databases and gray literature were systematically searched from inception to November 2018. STUDY SELECTION CRITERIA All studies that investigated constructs related to the health of current or former baseball players were included. DATA SYNTHESIS Data were extracted for thematic summaries. RESULTS Ten thousand five hundred seventy-four titles/abstracts were screened, and 678 studies were included. Ninety percent of articles included only baseball players playing in the United States, 34% of articles investigated professional baseball players, and 11% studied college baseball players. Five hundred eighty-three (86%) studies investigated musculoskeletal health, 77 (11%) general health, and 18 (3%) psychological health. Injury incidence (injuries per 1000 athlete exposures) ranged from 0.7 to 3.6 in professional, 4.7 to 5.8 in college, and 0.8 to 4.0 in high school baseball. Among baseball players, 31% to 50% reported regular tobacco use. There was li