Reliability Analysis of Footscan Plate System in Measurement of Plantar Pressure of Spastic Diplegia Children

This study was aimed at evaluating the reliability of Footscan plate system when measuring pressure in spastic diplegia children (CP). Eighteen CP and 36 typical developed counterparts (TD) with similar age, height and weight were recruited and their plantar pressure was measured in at least five trials. Three-mask model was applied and plantar regions were divided into: forefoot, mid foot and hind foot, under which peak pressure (PP) (N/cm2), relative pressure time integral (PTIrel) (%) and relative contact area (CArel) (%) were calculated. Coefficient of variance (CoV) and intra class coefficient (ICC) were explored for each variable and region. Our outcomes show that in terms of CP, with the increasing of test times, ICC of PP increased, while those of PTIrel and CArel were lowered; additionally, ICC of TD of each pressure variable successively improved. A similar tendency was found for CoV. Considering entire feet of CP and five measurements, reliability of CArel was the best in the three areas; whereas PP and PTIrel were demonstrated to be less reliable, except for the midfoot area. In contrast, reliabilities of TD were shown to be good for all pressure variables under all three regions. Overall, reliability of Footscan plate system in the study of CP was moderate in most variables and under most plantar regions. Thereby, by increasing the test times to no less than five, this protocol could be applied in the clinical and scientific investigation of CP children.