The Effect of Foot Supports on Ground Reaction Force Patterns

159 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987.Forefoot deformities are the etiology of various pathomechanical conditions of the foot. A forefoot varus or valgus deformity can create changes in the ground reaction force patterns, causing increased stress to the anatomical structures of the foot. Foot supports reestablish proper alignment of the forefoot, resulting in a more typical ground reaction force pattern.The purpose of this investigation was to determine the effect of foot supports upon ground reaction force patterns for individuals with forefoot deformities during walking. In addition, the ground reaction force patterns for individuals with forefoot deformities were compared to ground reaction force patterns obtained from subjects with normal foot types while walking.Twenty-two females and one male, ranging in weight from 480 to 734 newtons and in age from 21 to 57 years, served as subjects. Five subjects had no forefoot deformity, nine had a forefoot varus, and nine had a forefoot valgus deformity. All subjects wore standardized shoewear. The subjects with forefoot deformities wore three types of foot supports fabricated with materials of varying densities.Ground reaction force data were collected while walking barefoot. Subjects were instructed to wear shoes for 160 hours, and to wear each pair of foot supports 40 hours. The walking cadence, determined from the barefoot trials, was duplicated by each subject prior to the final testing session. Each subject performed three trials for each treatment, for a total of 15 trials. Ten characteristics of the ground reaction force pattern were measured and evaluated using a two-way analysis of variance with repeated measures. The.05 level of significance was selected.No significant differences were found between the normal and forefoot deformity groups. The analyses for the forefoot varus and valgus groups resulted in several significant findings for the foot type-treatment interaction, as well as among the five foot treatments.Based on the results, individuals with forefoot deformities do not require foot supports, if using shoewear with increased rearfoot stability. However, individuals with forefoot valgus deformities would require foot supports. The density of the material used to fabricate the foot supports was not significant.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD