The influence of body weight, body mass index and gender on plantar pressures: results of a cross-sectional study of healthy children's feet.

The purpose of this study was to determine if plantar pressure data in 4-7 year old children with normal development: (1) required normalising by body mass and/or body mass index and (2) should be separated or pooled for boys and girls. The outcome will guide the management of plantar pressure data in future work investigating changes in plantar pressure distribution with increasing age. In a cross-sectional design, 98 British children (45 girls) with no orthopaedic, neurological or developmental disorders provided plantar pressure measurements during walking. Peak plantar pressure and plantar pressure time integrals were obtained from nine areas under the foot: calcaneus, medial and lateral midfoot, each of the five metatarsals and the hallux. Body weight and body mass index demonstrated low and weak degrees of association (r≤0.48, p<0.05) with plantar pressure data. Boys and girls showed no difference in plantar pressures (p<0.05). Plantar pressure data for 4-7 year olds does not require normalisation with body mass or body mass index, and can be pooled for boys and girls.