Body Posture Mediates The Association Between Physical Fitness And Mental Health In Children

PURPOSE: Physical fitness is a crucial indicator associated with the long-term risks of mental disorders in children. In recent years, the prevalence of poor body posture has also been on the rise, which can affect children’s physical activity performance and reduce their sense of achievement in physical activity, in turn having adverse effects on their Physical Fitness Index (PFI). Evidence has shown that poor body posture is related to children’s mental health status. Given the rising prevalence of mental disorders among children, identifying the modifiable associations between body posture, PFI, and mental health is critical. The purpose of this study was to examine the mediating role of body posture in the association between physical fitness and mental disorder risks among children. METHODS: 1,394 children aged 8-10 were recruited from 4 primary schools in Beijing using a cluster sampling method. The Strengths & Difficulties Questionnaire (SDQ) assessed mental health status, including emotional symptoms, ADHD, conduct problems, and peer relationship issues. PFI was evaluated through lung capacity (cardiorespiratory fitness, CF), bent-leg curl-ups (muscular endurance, ME), 50-meter sprint time (muscular power, MP), sit-and-reach test (flexibility), and jump rope test (agility). Body posture indicators include forward head posture, uneven shoulders, scoliosis, and arch height. Data were analyzed using R 4.4.2, with regression analysis and structural equation modeling (SEM) with reverse mediation employed to explore the relationships between body posture, PFI, and mental health. RESULTS: Poor body posture influenced CF, ME, MP, and agility with coefficients of -72.28, -3.05, -0.29, and -5.45, respectively (P < 0.05). Poor PFI increased the risk of mental health problems in children by 74.03% (P < 0.05), while poor body posture increased the risk by 36.24% (P < 0.05). Mediation analysis revealed that the direct effect of PFI on mental health was 81.16%, and the indirect effect through body posture was 18.84%. CONCLUSION: Poor body posture significantly affected children’s PFI, and body posture has significant medication effect between PFI and mental health for children. It warrants further investigation of the effectiveness of body posture PA to promote both PFI and mental health for children. Supported by: This work was supported by the Major Project of Philosophy and Social Science Research from the Ministry of Education of China, project number: 20JZD052.