The effect of heel elevation on strain within the plantar aponeurosis: in vitro study

Mild, temporary reduction of symptoms from plantar fasciitis have been reported with the use of high heeled shoes (i.e. cowboy boots, ladies pumps). However, little is known on how heel elevation may contribute to a decrease in the pain and inflammation. The aim of this study was to quantify strain in the plantar aponeurosis in cadaveric feet with the use of various heel elevation configurations. An in vitro method that simulated "static" stance was used to determine the loading characteristics of the plantar aponeurosis (n = 12). Heel elevation was evaluated with blocks placed beneath the heel and with a contoured platform that simulated the arch profile of a shoe at three different heel heights (2.0, 4.0, 6.0 cm) with a level plane serving as the control. Strain in the plantar aponeurosis decreased with elevations of the heel that simulated the arch profile of a shoe at load levels (337, 450 N) (P < 0.05). Elevations of the heel with blocks did not significantly affect strain in the plantar aponeurosis (P < 0.05). Contrasting results of some specimen limbs compared with the overall means suggests that the influence of heel elevation on loading of the plantar aponeurosis may be dependent on individual variation and foot structure differences. Therefore, clinicians should be cautious in recommending heel elevation as a treatment for plantar fasciitis since some subjects may not achieve the desired decrease in plantar aponeurosis strain.