Challenging present concepts in compression therapy: static stiffness index is not consistent and not clinically relevant.

Once a circumferential force is delivered to a limb by a compression device, assuming the tension within the device remains constant, any change in the total force is dependent upon a change in circumference of the limb, with the rate of change (excluding fabric creep) being dependent on the stress strain curve of the device. This article addresses the pre-conceived and well-accepted principle that interface compression delivered by a compression device substantially increases with the position of the limb, based on the positions of sitting (non-weight bearing) to standing and/or during muscle activity (ankle dorsiflexion). Using engineering parameters and clinical measurements, the authors demonstrate that changes in interface pressure are minimal if any, and that the current concept should be modified accordingly. Declaration of interest: This study was sponsored by Carolon. L. Reid, and S. Kravitz are employees of Carolon. M. Hegarty-Craver has received monetary compensation as a researcher for Carolon.