Systematic objective evaluation of flexible flat foot and a rationale of orthotic treatment

A systematic evaluation on flexible flat foot and rationale for orthotic treatment has been conducted. A new parameter, Contact Force Ratio (CFR) was developed from dynamic foot print measurement to reflect foot function and classify foot types. This is a measure of midfoot loading during gait. The reliability of the CFR method has been proven by results of intratester and intertester reliability tests. In a one-year cross-sectional survey dynamic footprints of children in the 4 to 18 years growth age group were measured using the Tekscan pressure sensing mat. The mean CFR and standard deviation were calculated for each age group. In general, the CFR decreased from 4 to 10 years of age and plateaued from 10 years until 12 years of age and then increased until 15 to 16 years of age. The mean CFR of each age group plus one standard deviation was set as the cut-off value to define abnormal low arch. A one-year cross-sectional survey was conducted to examine arch growth patterns. With reference to the definition of abnormal low arch classified by the CFR method, CFR decreased in the normal arch group and increased in the abnormal low group.; Using low temperature thermoplastics, a non-weight-bearing foot impression method was developed to facilitate a consistent orthotic design for abnormal flexible flat foot. In a one-year pilot study, the CFR of the orthosis intervented abnormal low arch group decreased over the one-year time-frame. In instances where there was no orthotic intervention, the CFR increased continuously. With orthotic intervention, the peak medial force in push off and the peak internal tibial rotation in mid stance were reduced. The power absorption at heel strike was reduced and power generation during push off was increased with the result that propulsion became more effective.; Whilst the relatively short period over which the study was conducted may be insufficient to prove the efficacy of the treatment the evaluation method developed may serve as a starting or reference point for people who would like to pursue further clinical studies in this area.