Table 4. Stud ies reporting on the relationship between obesity and musculoskeletal disorders (n = 4).

Author and publication year	Study design	Country	Sample size (n)	Age range or mean age	Obesity definition	Outcome definition	Outcome identification	Covariates	Results	Study quality (based on NOS score)
Chen 1 et al.	Prospective cohort	Taiwan	580 (283 girls)	3–5 years	Taiwanese FDA definitions of obesity for children and adolescents	Flatfoot = AB distance by CSI > 62.70%. CSI is defined as the ratio of the minimum width of the midfoot arch region (B) to the maximum width of the metatarsus region (A)	Clinician measurement using digital footprint mat	Age	Prevalence of flatfoot was significantly higher in obese children	Low risk of bias (6/9)
Chen 2 et al.	Cross-sectional	Taiwan	1598 (765 girls)	3–6 years	Taiwanese FDA definitions of obesity for children and adolescents	Clinical presentations of malformation of the medial longitudinal arch in a weight bearing position	Clinician examination of foot	Age, sex, joint laxity, W sitting	Obese status increased the odds of bilateral flatfoot, but did not increase odds of unilateral flatfoot (Bilateral OR 1.90; 95% CI 1.22–2.95; unilateral OR 1.39; 95% CI 0.80–2.41)	Low risk of bias (6/8)
Ezema et al.	Cross-sectional	Nigeria	474 (253 girls)	6–10 years	CDC growth charts	Plantar arch index value >1.15	Ink footprint test	-	Prevalence of flatfoot was significantly higher in obese children	Low risk of bias (7/8)
Riddiford-Harland et al.	Case control	Australia	150 (98 girls)	8.3 years	Cole et al.	Clinical presentation of reduced foot arch on ultrasound	Ultrasound	Age, sex	Prevalence of flatfoot was significantly higher in obese children	Low risk of bias (8/9)

Abbreviations: CDC, Centers for Disease Control and Prevention; NOS, Newcastle–Ottawa Scale.