Risk factors for elbow injuries among young baseball players

Abstract

Hypothesis: There are some risk factors that could predispose a young baseball player to elbow injuries.

Materials and methods: Study participants were 294 baseball players aged 9 to 12 years old. A questionnaire, physical examination, and ultrasound imaging to investigate elbow injuries were performed. Data for the groups with and without elbow injuries were analyzed statistically using multivariate logistic regression models.

Results: Ultrasound imaging showed that 60 participants had elbow injuries, including medial epicondylar fragmentation in 58 and osteochondritis dissecans of the capitellum in 2. The odds ratio (95% confidence interval) of the risk factors that statistical analysis showed were significant were age older than 11 years, 2.82 (1.30-6.10); height exceeding 150 cm, 2.02 (1.07-3.82); pitching, 4.50 (2.42-8.37); daily training, 1.96 (1.02-3.79); range of motion (ROM) of external rotation of the shoulder below 130 degrees , 1.98 (1.01-3.87); muscle strength (MS) of external rotation of the shoulder exceeding 80 N, 4.11 (1.47-11.55); and MS of internal rotation of the shoulder exceeding 100 N, 2.04 (1.08-3.90).

Discussion: Risk factors for elbow injuries are age, height, pitcher, days of training, grip strength, range of motion of external rotation of the shoulder, and muscle strength of the shoulder.

Conclusion: As new information, our results suggest that decrease of ROM of external rotation of the shoulder and increase of MS of external and internal rotation of the shoulder predispose elbow injuries.