Calculating the Pressure and the Stiffness in Three Different Categories of Class II Medical Elastic Compression Stockings

Abstract

BACKGROUND Medical elastic compression stockings (MECS) are currently classified according to the pressure they exert at the ankle at the point of its minimum girth (B level). Despite this classification, there are considerable differences between MECS belonging to the same compression class from the same manufacturers and between different manufacturers. This makes it difficult for the clinician to choose the most suitable MECS for the patient. The stiffness may be used to distinguish between MECS of different brands. OBJECTIVE To calculate the pressure and the stiffness at the B level in three categories of class II MECS from nine different brands. METHODS Nine different brands of class II MECS that were divided into three categories (flat-knitted custom-made, classic round-knitted ready-made, and modern (ultrathin) round-knitted ready-made) were tested. The tension of the textile of the MECS was measured with the Instron® tester. The pressures and stiffness at the B level were calculated. RESULTS The pressures exerted by flat-knitted custom-made MECS were higher than those exerted by the ready-made round-knitted MECS. Surprisingly, the former showed higher pressures than those published by the European Committee for Standardization. A wide range of stiffness was observed within the different brands and within the three different categories of MECS. CONCLUSION Despite their assignment to compression class II, all nine brands of MECS that were tested had widely ranging stiffness. This would indicate that the stiffness is an additional important characteristic for distinguishing between MECS from different brands, which should be taken into account by the clinician in selecting the most suitable MECS for the patient.