Effects of skin pressure from compression legwear on resting salivary cortisol and urinary catecholamines excretion in women.

BACKGROUND: The benefits of compression legwear (CL) have been demonstrated in the improvement of vascular function and venous return of the lower extremities, but their effect on autonomic nervous system (ANS) activities and human stress response remain controversial. OBJECTIVE: To investigate the possible effects of CLs on ANS activities and in inducing stress on the human body. MATERIALS AND METHODS: Resting salivary cortisol and urinary catecholamine (adrenaline and noradrenaline) excretions were examined in 12 healthy women. The effects of different skin pressure levels exerted by CL were studied by conducting a 4-hour prolonged standing and sitting wear trial with intermittent sampling of the aforementioned biochemical parameters. RESULTS: No statistically significant differences in resting salivary cortisol and urinary catecholamines were found between control and different clothing pressure conditions (light, mild, moderate, and strong), although the secretion of salivary cortisol (SSC) showed a significant decrease during the 180 minutes of the testing period that was maintained up to 10 minutes after the CL was removed for the studied pressure conditions. Urinary excretion of adrenaline and noradrenaline decreased with increasing pressure levels and was lower in response to higher clothing pressure when tested in the afternoon. CONCLUSION: Constant pressure exerted by CL did not cause any stimulation of the sympathetic nervous system. The prolonged wearing of CL while standing or sitting did not induce any stress on the human body, suggesting that CL can be safely used in the treatment of patients with venous disorders of the lower extremities.

Effects of graduated compression stockings with different pressure profiles on lower-limb venous structures and haemodynamics.

INTRODUCTION: Graduated compression stockings (GCS) are one of the essential mechanical therapeutic approaches used in prevention and treatment of venous diseases. Pressure levels and gradient distribution are the two determined parameters influencing the performance of GCS products. However, the effects of GCS with different pressure profiles on venous function remain controversial in practical use. OBJECTIVE: To determine the physiological effects of GCS with different pressure levels and gradient distribution profiles on the venous function of the lower extremities. METHODS: At specific testing points along the long and short saphenous veins (LSV, SSV) and popliteal veins (PV) of the lower extremities, Doppler ultrasound techniques were used to examine venous cross-sectional areas (VA, cm(2)), the venous peak blood flow (PVpeak, cm/sec) and venous mean blood flow (PVmean, cm/sec) velocities in twelve female subjects wearing GCS with varying pressure profiles in a controlled laboratory environment. The Doppler examination was conducted three times during the 4-hour period (after wearing GCS for 1 minute, 70 minutes, and 170 minutes) in each subject. RESULTS: The pressure levels of GCS and duration of wear had statistically significant influences on the venous anatomy and venous haemodynamics. GCS with light, mild, moderate and strong pressures increased the popliteal PVpeak by 9.64%, 25.74%, 29.91% and 26.47%, respectively, and significantly decreased the VA. The GCS maintained these venous haemodynamics over time. No significant differences in blood flow were found between the mild, moderate and strong pressure GCS. CONCLUSION: The application of GCS with light and mild compression profiles appear to be effective in achieving a reduction in venous dilation and venous pooling, and improving venous return in the lower extremities. GCS with lighter pressures may be more suitable for subjects whose daily work requires long-term inactive standing or sitting, and GCS with mild pressure appear to be sufficient for most clinical applications.

Skin pressure profiles and variations with body postural changes beneath medical elastic compression stockings.

BACKGROUND: Medical elastic compression stockings (GCSs) are one of the most widely used mechanical compression approaches to relieve venous disorders of the lower limb. The skin pressure profiles applied by compression stockings may be altered with body postural changes, thus exerting influences on their therapeutic efficiency. OBJECTIVES: To examine and quantify objectively the skin pressure distribution and magnitude beneath GCSs with body postural changes, and to analyze the possible reasons for skin pressure variations. METHODS: The pressure levels of four different kinds of commonly used GCS were measured using piezoelectric sensors and a multichannel measuring system in six female healthy volunteers in 10 different body positions. RESULTS: Body postural changes significantly influenced the skin pressure profiles (P < 0.001). Skin pressures at the ankle and on the anterior side of the leg were always highest when tested in all positions. Extension and flexion of the knee joint significantly influenced the skin pressure at the anterior and posterior aspects of the leg, especially when tested in the sitting position with the knee flexed at 90 degrees and in the supine position with the knee flexed at more than 90 degrees (P < 0.001). Plantar flexion of the ankle joint, such as up-heel standing and heel-off walking, significantly increased the skin pressure in the ankle region. Contraction, extension, and relaxation of the calf muscle did not produce large fluctuations in skin pressure when tested in positions with full knee extension. CONCLUSIONS: Body postures may be one of the most important factors influencing the skin pressure profiles applied by compression stockings. The anatomic structure of individual legs, the special design of compression stockings, and the physical properties of stocking materials also influence skin pressure variations at different tested locations in different body positions. Appropriate leg postural changes and exercise may improve the therapeutic effectiveness of GCSs.

Objective evaluation of skin pressure distribution of graduated elastic compression stockings.

BACKGROUND: The beneficial effects of graduated elastic compression stockings (GCSs) have been demonstrated. However, their pressure performances are variable and unstable in practical applications owing to many influencing factors. Comprehensive assessment of skin pressure profiles may help elucidate the mechanisms of action of compression stockings. OBJECTIVE: The objective of this study was to quantify and objectively evaluate the magnitude and distribution of skin pressure applied by different GCSs and to analyze the possible reasons influencing the stocking pressure performances. METHODS: Six healthy females were required to wear eight kinds of GCSs with different pressure levels while standing upright. The skin pressures of 16 different positions located in four heights and four directions of the lower limb were measured and recorded by FlexiForce interface pressure sensors (Tekscan, Inc., Boston, MA, USA) and a multichannel measuring system. RESULTS: The pressure gradients, pressure levels, and testing locations significantly influenced skin pressure (p < .001). All tested GCSs exerted the highest pressure at the ankle region, and the pressure gradually decreased toward the thigh, which follows the gradient design of GCSs. However, many of them failed to produce the perfect pressure gradients from the ankle region to the calf region. Obviously, reversed pressure gradients occurred in the medial side of the leg, where the pressure at the ankle region was lower than that on the prominent part of the calf by 36% on average. GCSs with higher pressure levels applied higher skin pressure on the lower limb. The pressure at the anterior side was far higher than that in the medial and lateral directions. The distribution patterns of skin pressure at transverse sections were similar to the anatomic outlines of cross sections of the leg. The measured average ankle pressure of all tested GCSs did not reach the pressures specified by the manufacturers. CONCLUSION: Skin pressure distributions and magnitudes applied by GCSs were significantly influenced by the locations of testing points in terms of height and direction, which are determined by the specific anatomic structure and body shape of individual human legs and potentially influenced by the pressure sensor and testing methods.