Foot loading patterns in normal weight, overweight and obese children aged 7 to 11 years

BACKGROUND: Childhood obesity is thought to predispose to structural foot changes and altered foot function. Little is currently understood about whether similar changes occur in overweight children. The aim of this study was determine foot loading characteristics in obese, overweight and normal weight children aged 7 to 11 years during level walking. METHODS: Dynamic plantar pressures were measured in 22 obese, 22 overweight and 56 normal weight children recruited from local primary and secondary schools in East London. Peak pressure, peak force, normalised peak force, pressure–time and force-time integrals were analysed at six regions of the plantar foot: lateral heel, medial heel, midfoot, 1st metatarsophalangeal joint, 2nd-5th metatarsophalangeal joint and hallux. A one-way ANOVA was used to test for significant differences in variables across the groups. Where differences existed Tukey post-hoc tests were used to ascertain the location of the difference. RESULTS: Children who were obese and overweight demonstrated significantly (p<0.05) higher peak pressures and peak forces as well as significantly higher force-time and pressure–time integrals under the midfoot and 2nd-5th metatarsal regions. After normalisation of peak force, similar trends existed where the obese and overweight children demonstrated significantly (p<0.05) greater loading at the midfoot and 2nd-5th metatarsals. CONCLUSION: Findings from this study indicated that overweight children, as young as seven, displayed differences in foot loading during walking, when compared with normal weight children. These findings were consistent with loading patterns of children who were obese and suggest that early assessment and intervention may be required in overweight children to mitigate against the development of musculoskeletal complications associated with excessive body mass.