Association Between Musculoskeletal Pain and Psychological Stress Responses in High School Baseball Players: A Cross-sectional Study

BACKGROUND: Musculoskeletal pain could represent a psychological stressor in adolescent athletes. However, few epidemiological studies have investigated this association. PURPOSE: To assess the relationship between musculoskeletal pain (shoulder, elbow, wrist, and low back) and psychological stress responses in high school baseball players. STUDY DESIGN: Cross-sectional study. METHODS: Participants comprised male Japanese high school baseball players who had completed a questionnaire as part of their annual medical evaluation in 2016. Experiences of shoulder, elbow, wrist, and low back pain during the previous season were investigated. Pain severity was graded as 1 (mild, playing without interference), 2 (moderate, playing with interference), or 3 (severe, could not play because of pain). The Stress Response Scale–18 was used to measure stress response: low, medium, rather high, and high. Prevalence rates of shoulder, elbow, wrist, and low back pain and their association with psychological stress responses were investigated using univariate and multivariable analyses. RESULTS: A total of 944 players (223 pitchers and 721 fielders) were included in this study. Their mean age was 16.1 ± 0.6 years, and 66% were high school juniors, while 33.6% were seniors. In pitchers, the prevalence rates during the previous year of severe (grade 3) interference with playing because of elbow, shoulder, wrist, and low back pain were 21.5% (n = 48), 19.3% (n = 43), 3.6% (n = 8), and 18.4% (n = 41), respectively, whereas in fielders, the respective prevalence rates were 17.1% (n = 123), 17.9% (n = 129), 6.7% (n = 48), and 19.3% (n = 139). After adjusting for confounding factors (playing on a top-performing team, high school grade level, and all other sites of musculoskeletal pain), the authors found significant associations in pitchers between severe experiences of elbow pain and low back pain and medium to high psychological stress responses (odds ratio, 2.64 [95% CI, 1.32-5.39], P = .006 and odds ratio, 2.32 [95% CI, 1.12-4.89], P = .024, respectively). No significant associations were seen between musculoskeletal pain and psychological stress responses in fielders. CONCLUSION: In the current study, elbow and low back pain were associated with stronger psychological stress responses compared with other musculoskeletal pain in high school baseball pitchers.