Development of healthy children's feet--nine-year results of a longitudinal investigation of plantar loading patterns.

The purpose of the present study was to provide normative data for foot loading patterns and foot form parameters in order to support decisions about the normal or abnormal development of the growing foot during childhood. In a longitudinal design, 36 healthy German children were followed over the course of nine years. The children had a mean age of 14.6 ± 1.8 months at the first appointment and 122.8 ± 2.0 months at the last appointment. The children participated in 17 measurement appointments every 3, 6 or 12 months. Dynamic foot loading was evaluated with plantar pressure measurements during walking and static footprints were taken to determine changes in foot form. During the investigation period an increase of peak pressures of the total foot by 190%, of the relative maximum force of the total foot by 20% and the foot length by 90% was observed. A decrease for the relative maximum force under the midfoot (63%) and for the arch index (49%) could also be demonstrated. Furthermore, body height showed a significant influence on foot length and midfoot width. Body weight had a significant influence on the static parameter midfoot width. Between genders, boys showed a significant wider midfoot and a smaller forefoot contact area as compared to girls. The established database can be used as comparative values for clinical decisions about the normal foot development.