Techniques for Comparison of Shoe Inserts During Stance

Abstract

OCCUPATIONAL APPLICATIONSPadded shoe inserts might be used to ameliorate foot discomfort for individuals who stand for extended periods while at work. We present four measurement variables with the potential to evaluate shoe inserts. Three of them proved useful for discriminating between two types of inserts. We also found that both inserts were better than barefoot, based on subjective responses, ankle muscle activity, and postural sway. However, a laminated insert appeared superior for enhancing comfort and decreasing superfluous movements.TECHNICAL ABSTRACT Background: Standing upright is a fundamental characteristic of human function and is required in several spheres of human occupation. When standing is prolonged, fatigue, discomfort, and pain within the lower extremities are common. One method of addressing this problem is the use of padded inserts in the shoes. Techniques for evaluating the efficacy and relative merits of different shoe inserts are needed. Purpose: We used four different techniques to compare the effectiveness of two types of shoe inserts while standing. Methods: Subjects (N = 19) stood for 30 min on a force plate under three conditions: barefoot, wearing an over-the-counter insert, and wearing a laminated custom foot insert. Four dependent variables were: (1) visual analog scale; (2) electromyography of muscles crossing the ankle joint; (3) Center of pressure excursions; and (4) peak plantar contact pressures. Data were analyzed with repeated-measures analysis of variance. Results: The visual analog scale, accumulated electromyography, and center of pressure excursion each discriminated between the three conditions and generally indicated that the custom foot insert was more comfortable than the over-the-counter insert. Peak plantar pressure was reduced by both inserts compared to barefoot, but did not discriminate between the two inserts. Conclusions: These results suggest that visual analog scale, center of pressure excursion, and electromyography can be used to evaluate and compare shoe inserts and that some inserts (custom foot insert) might be better at providing standing comfort than others (over-the-counter).