Interest of a standardized treadmill test to evaluate pressure drops and stiffness indices under short stretch bandages

Abstract

Introduction: Under short stretch bandages (SSB), the pressures drop over time. These pressures are documented in non standardized-way and vary from one study to another. Objective: A standardized stress test on a treadmill should help to better understand this evolution and thus to document with more precision the behavior of 3 bandages in use. Materials and Methods: Three bandage kits (Urgo K2, Kit Biflex and a kit consisting of padding + 2 cotton SSB2 were tested in 30 subjects (60 legs) before and after a treadmill test (3 km/h, 6% slope for 30 min or 1.5 km). Results: Before the test, the bandages were applied with nonsignificantly different resting interface pressures (respectively 40.58 ± 2.7 mmHg, 41.05 ± 2.17 mmHg, 38.16 ± 2.98 mmHg). When standing, the pressures were significantly different between Urgo K2, Kit Biflex and SSB2(55.58 ± 6.15 mmHg, 57.3 ± 6.53 mmHg versus 62.3 ± 5.07 mmHg for SSB2). Similarly, the static stiffness indexes (SSI) showed significant differences (15 ± 5.05mmHg and 16.25 ± 6.28 mmHg versus 24.13 ± 4.65 mmHg for SSB2). After the test, resting pressures drop but more significantly under the SSB2 compared to the other 2 multilayer bandages (resting pressures: 31.95 ± 2.66 mmHg and 34.61 ± 2.28 mmHg vs. 25.95 ± 3.15 mmHg for SSB2). However, the SSI is not significantly different from the SSI calculated before the treadmill test (15.41 ± 4.44 mmHg and 15.66 ± 4.85 mmHg vs. 25.06 ± 4.98 mmHg). Conclusions: The treadmill test makes it possible to quantify and to compare the drop in pressure under different bandages in the same conditions. This test could be useful in clinical research before the clinical phases of development, especially in the case of venous leg ulcer. On the other hand, in case of mixed ulcers, the drop in pressure in lying position in multilayer bandages ensure a continuation of the arterial influx in case of mixed ulcers.