Bio-Mechanical Aspects of the Tourniquet

Abstract 1. (1) There is no simple relationship between the readily measurable tourniquet pressure at the surface of the limb and the stresses induced in nerves and vessels within the limb. 2. (2) Theoretical work suggests that radial stresses (pressure) increase towards the centre of a limb subjected on its surface to pressure from a tourniquet. In addition, since limb tissues display some of the properties of an elastic solid, various shearing stresses are developed. These may be even more harmful than radial pressure. 3. (3) There is clearly a need for more precise monitoring of pressures and stresses within the limb subjected to tourniquet pressures. It may be possible, ultimately, to resolve the vexed question of the relative importance to be accorded to the level of applied external pressure and its duration in clinical practice. 4. (4) Current work is directed to the measurement of pressures at various points within a limb under a tourniquet in order to establish or refute the theoretical hypothesis advanced.