Abstract
OBJECTIVES: Injuries in young baseball players are on the rise. However, there are few large-scale related to injury prevention activities. We have continued an injury prevention project in Kyoto, Japan since 2010. The aim of this study was to verify the preventive effect of our project. METHODS: We offered medical screening of elbow for elementary and junior high school players. We examined their elbow manually, performed ultrasonography and guided the players how to check their elbow themselves. Additionally, we instructed baseball coaches and parents regarding injury prevention annually. In this study, a cumulative total of 2624 baseball players (mean age 11.0±0.6) who participated in our injury prevention project (2010-2016) were enrolled. We asked them to answer the questionnaire to investigate the experience of elbow pain and evaluated the tenderness of humeral medial epicondyle and range of motion. Ultrasonography of humeral capitellum and medial epicondyle was examined. Subjects with abnormalities on ultrasonography were further examined through radiographic study and osteochondritis dissecans of the humeral capitellum (OCD) was diagnosed. Humeral medial epicondyle apophysitis was diagnosed with abnormalities of ultrasonography, and physical findings. The annual incidence were investigated and analyzed statistically. P < 0.05 was considered significant for all statistical analysis. RESULTS: The mean prevalence rate of OCD was 1.1% and flexion restriction was 12.3%. There were no significant differences in annual incidence. However, the experience rate of elbow pain was 14.4% in 2010 and 4.4% in 2016, tenderness of humeral epicondyle was 32.2% and 5.8%, extension restriction was 12.5% and 6.9%, and humeral medial epicondyle apophysitis was 22.1% and 5.3%, respectively, that significantly reduced year by year (Table 1). CONCLUSION: There has been increasing recognition for the importance of preventing the overuse injuries among young baseball players. However, large-scale and longitudinal evaluation studies for preventing elbow injuries have not been reported. The prevalence rates of elbow injuries have generally reduced year by year, which indicates that annual medical screening and educational project for young baseball players, coaches and parents would be an effective approach for preventing elbow injury.