ISAKOS: 2019 Congress in Cancun, Mexico

2019 ISAKOS Biennial Congress ePoster #2110


Prevention of the Shoulder Injuries Among Young Baseball Players: An Eight-Year Longitudinal Study

Yoshihiro Kotoura, MD, PhD, Kyoto, Kyoto JAPAN
Yoshikazu Kida, MD, PhD, Kyoto JAPAN
Toru Morihara, Kyoto, Kyoto JAPAN

Kyoto Chubu Medical Center, Nantan, Kyoto, JAPAN

FDA Status Not Applicable


Prevention study of the shoulder injuries



Shoulder injuries among young baseball players are on the rise. We have conducted preventive activities for young baseball players in one area of Kyoto, Japan from 2010. The purpose of this study was to investigate the shoulder injuries among young baseball players and verify the effect of our activities.
Subjects and Methods: Subjects were 2052 elementary baseball players from 9 to 12 years (mean, 10.7±0.9 years) who participated in the medical check from 2010 to 2017. We examined their shoulder manually and guided them on how to check themselves. Additionally, we held the workshop twice a year for baseball coaches and instructed parents regarding injury prevention. The shoulder of each subject’s throwing arm was assessed using a questionnaire and physical examinations. We reviewed the data longitudinally and verify the effect of our activities.


Present shoulder pain while throwing was significantly decreased year by year; from 19.4% in 2010 to 3.4% in 2017. The mean rate was 9.2%. Past shoulder pain while throwing was significantly decreased from 28.1% to 10.6%. Tenderness of the proximal humerus was significantly decreased from 19.4% to 4.6%. However, there was no significant difference in the hyper external rotation test and mean rate was 6.3%.


There has been the recognition for the importance of preventing the overuse injuries among young baseball players. However, large-scale and longitudinal studies for preventing shoulder injuries have not been reported. In the present study, the present shoulder pain in elementary baseball players was almost 10%. Past eight years, shoulder pain and tenderness of the proximal humerus were significantly decreased year by year. It could be presumed that our activities have a positive effect on shoulder injury prevention.