The field of plantar pressure is poorly explored in developmental biomechanics, with scarcity of studies investigating functional characteristics and development of the infant weight-bearing foot. Specifically, the available research has focussed on plantar pressures captured from systematic gait protocols, ignoring data captured in real-world settings, and using discrete statistical approaches for the analysis. This thesis investigated foot function characteristics and development of 39 typically developing infants, as they attained three stages of motor development, namely pull to stand, the onset of walking and confident walking. This was achieved by a thorough analysis of plantar pressures originating from one of the largest data set collected in infancy, in a real-world, free-walking environment, implementing novel discrete and continuous approaches to plantar pressure data analysis. After the appropriateness of such methodologies have been established in this thesis, it has been demonstrated that 33 infants at the three stages of motor development showed unique yet common pressure patterns that perpetuated from pull to stand to confident walking (e.g., greater involvement of the forefoot regions, highest pressure applied in the heel). The application of pressure and its changes throughout stance were investigated through vector fields’ analysis of centre of pressure (COP) in 39 infants with Statistical Parametric Mapping (SPM). This chapter demonstrated changes in the anterior-posterior and medio-lateral components of the COP that underpinned modification of foot-ground interactions, occurring with a more stable and controlled foot placement towards the ground in confident walking stage. Finally, analysis of plantar pressures with SPM demonstrated increasing pressure in the medial heel, in the lateral and central forefoot, as well as decreasing pressure in the hallux and in the medial midfoot, highlighting that body weight and walking experience significantly predicted plantar pressure changes during walking in infancy. As a result, this thesis demonstrated, for the first time, that typical patterns of foot function in walking originates from early stages of bipedal upright locomotion. Alongside a cascade of complex neuromuscular-skeletal maturation, plantar pressures demonstrated also the quick establishment of the typical yet immature rollover pattern of the foot from the onset of walking, which originates after 2.3 months of independent walking experience. With this information, this thesis provided a set of typical developing data that can be used in both research and clinical practice to develop and improve future studies, enhance foot assessment as well as improve knowledge that can help interpret clinical findings and make decisions.
|Date of Award||Jul 2022|
|Supervisor||Stewart Morrison (Supervisor) & Carina Price (Supervisor)|