Doctor of Philosophy
University of Wollongong. School of Health Sciences
Riddiford-Harland, Diane L., Childhood foot structure and function: is this influenced by obesity?, Doctor of Philosophy thesis, University of Wollongong. School of Health Sciences, University of Wollongong, 2010. http://ro.uow.edu.au/theses/3307
Obesity in childhood has been associated with numerous negative health consequences, which can contribute to a reduced quality of life and poor long-term health prognosis. Although compromise to the musculoskeletal system of children as a result of habitually carrying excess adiposity has been reported, it is not clear how obesity affects the developing feet of young children. Identifying possible negative effects of excess body mass on the feet of overweight and obese children could assist in preventing future foot complications and in the design of appropriate interventions to promote healthy outcomes for these children. Therefore, the aim of this thesis was to systematically investigate the effects of overweight and obesity on foot structure and function in school-aged children.
This thesis aim was achieved through a series of studies, the first of which established a reliable protocol to quantify the midfoot structure of young children’s feet. Once this protocol was established four studies were conducted to examine structural and functional characteristics of the feet of prepubertal school-aged children (aged between 5 and 9 years) of varying body mass index. Parameters quantified in these studies included height, body mass, external foot dimensions, medial midfoot fat pad thickness, internal arch height, dynamic plantar pressure distributions and physical activity participation.
The combined results of these studies revealed that overweight and obese children’s feet are fatter and flatter than those of their non-obese counterparts. The medial midfoot fat padding in these overweight and obese children was thicker than that of non-obese children, although it did not appear to provide any functional protection for the feet of these overweight and obese children during walking. Dynamic plantar pressures generated by these school-aged children were positively associated with body mass and inversely associated with physical activity intensity. After these children participated in a weight-bearing physical activity intervention, their body mass and plantar pressure distributions were stabilised with no apparent effect of the program on their foot structure and function. Plantar pressures, however, remained high at program completion and the pressure-time integrals significantly increased from pre- to post intervention.
Based on the results of this thesis it is postulated that the developing feet of overweight and obese children may be at risk of foot pain, discomfort or dysfunction due to the high plantar pressures generated by these children due to their excess bodymass. Interventions designed to reduce pressures generated beneath the feet of overweight and obese school-aged children while still encouraging these children to participate in adequate levels of physical activity are warranted.