Body Mass Index and Hand Dexterity in School-Aged Children: A Cross-sectional Study of Gender-specific Task Performance and BMI Categories
Lekpa Kingdom David *
Department of Anatomy, Faculty of Basic Medical Sciences, University of Port Harcourt, Choba, Rivers State, Nigeria.
Avwerosuoghene Obakanurhe
Department of Anatomy, Faculty of Basic Medical Sciences, University of Port Harcourt, Choba, Rivers State, Nigeria.
Angela R. Wells
City University of Seattle, Washington School of Business, Healthcare Informatics and International Management, Seattle, WA, United States of America.
Philip A. Adewuyi
Department of Electrical Engineering, Wigwe University, Isiokpo, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Childhood body mass index (BMI) is often hypothesized to influence motor development, yet its specific association with hand dexterity remains unclear and inconsistently supported by evidence. This cross-sectional study examined the relationship between BMI and hand dexterity, compared dexterity performance across BMI categories, and assessed gender differences among school-aged children.
Methods: Seventy-nine (79) children aged 6–12 years (mean age: 9.24 ± 1.64 years; mean BMI: 15.90 ± 2.61 kg/m²) completed the Jebsen-Taylor Hand Function Test (JTHFT), which includes timed tasks such as writing, feeding, and object manipulation. BMI categories were stratified using WHO standards. Pearson correlations and independent t-tests analyzed BMI-dexterity relationships and gender differences.
Results: Results revealed weak, non-significant correlations between BMI and dexterity overall (r = 0.036–0.151, p > 0.05). No significant differences emerged across BMI categories (p > 0.05), though males showed subtle trends of higher BMI correlating with slower dominant-hand writing (r = 0.218, p = 0.09). Females exhibited stronger inter-task correlations (e.g., writing and picking objects: r = 0.620, p < 0.01), while males demonstrated dominant-hand task specificity (writing and picking: r = 0.819, p < 0.01). Gender comparisons revealed no significant differences in task performance (p = 0.33–0.61).
Conclusion: The findings suggest BMI’s influence on dexterity is minimal in this age group but may manifest subtly in gender-specific task coordination. Clinicians and educators should adopt holistic approaches integrating BMI monitoring with motor skill assessments to address potential developmental risks. Future research should explore longitudinal BMI-dexterity trajectories and body composition nuances.
Keywords: Body Mass Index (BMI), hand dexterity, school-aged children, gender differences, Jebsen-Taylor Hand Function Test (JTHFT), fine motor skills, Rivers state