Off-the-shelf in-shoe heel inserts: does cost matter?

OBJECTIVE A growing exercise culture has lead to an increase in the use of off-the-shelf heel inserts. While there are a variety of designs in a spectrum of cost ranges, probably the ease of availability and cost would mainly determine the choice of purchase. This study was designed to determine whether expensive designs provide better pressure attenuation under the heel than their less expensive counterparts. PARTICIPANTS AND DESIGN Six brands of off-the-shelf heel inserts were tested. Selection of these was based purely on their availability in all sizes. Cost per pair ranged from 6 pounds sterling to 30 pounds sterling. Thirty-five asymptomatic subjects walked on a 10 m walkway, once with no inserts and once with each pair of inserts. The Pedar in-shoe system recorded a range of parameters under the heel. SETTING Institute of Motion Analysis and Research, Ninewells Hospital and Medical School, University of Dundee. MAIN OUTCOME MEASURES Evaluation of plantar pressure parameters under the heel. RESULTS All inserts reduced peak pressure under the heel. Maximum force and pressure-time integral also decreased. Contact time generally increased with the use of inserts. Values of contact area with and without inserts were comparable. CONCLUSIONS No significant differences were observed under the heel between the pressure attenuation properties of the lowest-priced and the most expensive designs, and hence the less expensive inserts can be considered as good as the expensive brands. However, the endurance power of these inserts may differ and this should be evaluated.