Effect of Different Insole Materials on Kinetic and Kinematic Variables of the Walking Gait in Healthy People.

Abstract

There is a lack of data that could address the effects of off-the-shelf insoles on gait variables in healthy people. Thirty-three healthy volunteers ranging in age from 18 to 35 years were included to this study. Kinematic and kinetic data were obtained in barefoot, shoe-only, steel insole, silicone insole, and polyurethane insole conditions using an optoelectronic three-dimensional motion analysis system. A repeated measures analysis of variance test was used to identify statistically significant differences between insole conditions. The alpha level was set at P < .05. Maximum knee flexion was higher in the steel insole condition (P < .0001) compared with the silicone insole (P = .001) and shoe-only conditions (P = .032). Reduced maximum knee flexion was recorded in the polyurethane insole condition compared with the shoe-only condition (P = .031). Maximum knee flexion measured in the steel insole condition was higher compared to the barefoot condition (P = .020). Higher maximum ankle dorsiflexion was observed in the barefoot condition, and there were significant differences between the polyurethane insole (P < .0001), silicone insole (P = .001), steel insole (P = .002), and shoe conditions (P = .004). Least and highest maximum ankle plantarflexion were detected in the steel insole and silicone insole conditions, respectively. Maximum ankle plantarflexion in the barefoot and steel insole conditions (P = .014) and the barefoot and polyurethane insole conditions (P = .035) were significant. There was no significant difference between conditions for ground reaction force or joint moments. Insoles made by different materials affect maximum knee flexion, maximum ankle dorsiflexion, and maximum ankle plantarflexion. This may be helpful during the decision-making process when selecting the insole material for any pathological conditions that require insole prescription.