Factors associated with juvenile musculoskeletal dysfunction in children

The prevalence of sedentary behavior among children has increased owing to the popularity of video games and smartphones. Conversely, sports injuries caused by excessive physical activity (PA) at a young age have also been reported. The lack of PA or, conversely, excessive sports strain during childhood has resulted in changes in children, such as a decline in their basic physical ability. This article addresses “Juvenile Musculoskeletal Dysfunction (JMD),” a musculoskeletal dysfunction in children without a clear underlying disease, and its associated factors. This study was an adjunct to a birth cohort study in Hyogo, Japan. This study included 1217 children aged 8 years (568 males and 649 females). All children underwent physical examinations of single-leg stance, squatting, upper-limb elevation, and forward bending as the JMD screening. JMD was defined as the inability to perform one or more of the four physical movements, which included a questionnaire regarding their history of musculoskeletal pain and fractures. The parents of each patient participant completed the questionnaire regarding a history of musculoskeletal pain and fractures of their child. Factors associated with JMD were analyzed using logistic regression models. The prevalence of JMD was 36.0% (n = 438). The inability to perform “single-leg stance,” “squatting,” “upper limb elevation,” and “forward bending” was 8.6%, 10.3%, 6.4%, and 19.7% in all cases (male and female), respectively. In total, 6.8% (n = 83) had musculoskeletal pain and 9.2% (n = 112) had a history of fracture. The JMD group had a significantly higher prevalence of musculoskeletal pain and a greater history of fractures than the non-JMD group. Demographic factors such as obesity and sex (male) were associated with JMD (Odd ratios were 3.06 [95% Confidence interval [CI]: 1.62–5.79] and 1.98 [95%CI: 1.54–2.55], respectively). This study defined JMD using simple physical examinations and investigated its associated factors in 8-year-old children. JMD was found to be more common in males with obesity and was associated with a history of fracture, and musculoskeletal pain, while habitual physical activity showed an inverse association with JMD.