RESUMO
BACKGROUND: High-compression stockings over 40 mmHg are often difficult or even impossible to apply. A specific technique is frequently used to overcome this problem: a high-compression stocking is replaced by two or even three lower compression stockings that are applied on top of each other, thereby reducing the effort of application. To our knowledge, however, no study concerning therapeutic stockings has demonstrated that the forces exerted by two or three superimposed stockings are additive. OBJECTIVE: The objective was to evaluate if the pressures exerted by two or three superimposed elastic stockings are additive. MATERIAL AND METHODS: A series of measurements was performed in vitro using an apparatus fitted with a pressure sensor on four different premade elastic stockings applied separately and then superimposed. The actual pressure measurement obtained with superimposed stockings was compared to arithmetic sum of the pressures produced by each of the stockings used. RESULTS: The pressures produced by superimposed stockings are adequately predicted from the pressure given by each of the stockings used in the superposition, with correlation coefficients higher than 0.9. CONCLUSION: Under our experimental conditions, the superimposed elastic stocking pressures additivity hypothesis is confirmed. In vivo studies should be conducted to confirm those results.
