Development of healthy children’s feet—Nine-year results of a longitudinal investigation of plantar loading patterns Kerstin Bosch a, *, Joachim Gerß b , Dieter Rosenbaum a a Funktionsbereich Bewegungsanalytik, Klinik und Poliklinik fu¨r Allgemeine Orthopa¨die und Tumororthopa¨die, Universita¨tsklinikum Mu¨nster, Germany b Institut fu¨r Medizinische Informatik und Biomathematik, Universita¨tsklinikum Mu¨nster, Germany 1. Introduction In childhood, the human musculoskeletal system is subject to astonishing developmental processes of bony and muscular structures. Initial coordinated movements cause compressive and tensile stresses that are important for appropriately changing the shape of bones and muscles for future loading requirements [1]. Without these developmental processes the increased demands for an upright posture and gait would not be achieved. The foot is the connecting link between body and ground and therefore has an important task for the overall development of the musculoskeletal system. In order to fulfill the requirements for locomotion, the growing foot is subject to fundamental structural changes. This phase of functional alignment is essential for a physiological development of the foot. However, the development of the infant’s foot may reveal wide differences [2–4] so that the distinction between physiologic and pathologic development is difficult. Information exists about physiologic foot structures [5–9] and plantar loading [2–4,10– 14]. While most previous reports are based on cross-sectional investigations, a longitudinal evaluation of pediatric developments over a longer observation period is lacking. However, this kind of background data might be helpful for comparisons in order to appraise individual clinical cases. Therefore, the objective of this project was to provide information about the growth-related changes of foot shape and foot loading parameters in a longitudinal evaluation of healthy children from their first steps of independent walking to an age of 10 years. 2. Materials and methods In 1999 we began to recruit healthy German children that had recently started to walk freely. In spring, 2005 we reached the proposed number of 100 children and closed the recruitment. Previously, we observed 90 healthy children within the first four-year period for preliminary normative values for foot loading development [2]. Now, after a longer observation period, we were able to analyze 43 children over nine years in a longitudinal approach. The remaining children are still under observation. Seven of these 43 children were excluded: three due to missing an appointment, four because of pathologic foot developments. Therefore, complete data sets of 36 children (20 girls; 16 boys) were available for final analysis. The local Ethics Committee approved the investigation and the parents signed an informed consent form. Beginning at the age of six years, children were also asked to agree to participate. Exclusion criteria were orthopaedic, neurologic, systemic diseases or pre-term births. In the course of the study, 17 measurement appointments were required: five measurements during the first year (M1–M5; every three months) followed by eight semi-yearly appointments (M6–M13) until reaching the age for attending school. The final four yearly appointments (M14–M17) followed the children Gait & Posture 32 (2010) 564–571 ARTICLE INFO Article history: Received 27 April 2010 Received in revised form 23 July 2010 Accepted 6 August 2010 Keywords: Foot Children Plantar pressure distribution Foot development Normative values ABSTRACT 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. ß 2010 Elsevier B.V. All rights reserved. * Corresponding author at: Gait Lab – SPZ, St. Vincenz Hospital, Suedring 41, 48653 Coesfeld, Germany. Tel.: +49 0 2541 893007. E-mail address: boschk@uni-muenster.de (K. Bosch). Contents lists available at ScienceDirect Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost 0966-6362/$ – see front matter ß 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.gaitpost.2010.08.003