The effects of skin pressure by clothing on circadian rhythms of core temperature and salivary melatonin

Sports Bra Pressure: Effect on Body Skin Temperature and Wear Comfort

Sports bras are an essential apparel for active women, but may exert excessive pressure that negatively affects thermoregulation, thermal comfort and wear sensation. This study measures skin temperature changes during short durations of exercise on a treadmill with different bra pressures. The results based on 21 female subjects (age: 27.2 ± 4.5 years old) show that bras with more pressure at the underband or shoulder straps do not cause statistically significant skin temperature changes during exercise (p > 0.05). Nevertheless, compared to the optimal bra fit, significant differences in bra-breast skin temperature are found during running, cooling down and sitting when the bra pressure is increased (p < 0.05), particularly under bra cup (T1) in this study. The FLIR thermal images can visualize the skin temperature changes at abdomen throughout the four activity stages. Subjective sensations of bra thermal comfort, pressure and breast support are assessed. Despite the increased pressure on the shoulders and chest wall, perceptions towards thermal comfort remain unchanged. The perceived pressure comfort and support sensation amongst the 4 bra conditions are comparable. Interestingly, positive sensations of pressure comfort and breast support are perceived with a tight-fitting sports bra during treadmill exercise. High pressures induced by sports bras (>4 kPa) that habitually considered harmful to the human body may not lead to wear discomfort but enhance bra support sensation and a sense of security to the wearers.

A method for precise local pressurization in scar-repairing surgery

BACKGROUND

Pressure Garment Treatment (PGT) is currently recognized as an effective method to prevent scar formation or treat scar hyperplasia. Research on PGT remains controversial. These controversies indicate that PGT lacks reliable evidence of evidence-based medicine. Different studies on PGT need to be conducted under the same 'gold standard' so that different studies can be compared. We consider this 'gold standard' to be that the pressure remains stable within a confidence interval during treatment.

METHODS

We calibrated and verified the reference value of the sensor using a cuff of sphygmanometer.A pressure adjustable pressure system was obtained by installing a soft tissue expander on the pressure garment.Local pressure was adjusted by charging and releasing air.Subsequently, the flexible pressure sensor was placed on the upper arm of the healthy volunteers. We validated the compression system on healthy volunteers' forearms and AO standard prostheses (forearms).

RESULTS

Reference value of the sensor was calibrated on No.1 volunteer. Measuring repeated on No.2 and No. 3. The measurement was very reproducible. The test results in the experimental group showed that the local pressure gradually increased with the increase of the inflation of the airbag. However, the pressure at the opposite position of the forearm changed little.

CONCLUSIONS

Real-time pressure monitoring and pressure adjustment enable the pressure to be maintained at a certain value. Our study provides a new idea for the production of elastic clothing with the function of pressure measurement and pressure regulation, which may promote the accuracy and reliability of PGT.

Survey of national and local practice of compression therapy timing for burn patients in the United States

OBJECTIVE

Compression therapy (CT) has been an important, but debated, treatment for burn scars. To better understand one source of variation in observed outcomes after CT, an evaluation of CT timing of application is needed.

MATERIALS AND METHODS

Following IRB approval, 126 burn centers were contacted to complete a 17-question survey regarding the center's practice pattern for compression garment therapy. Locally, study subjects were identified between March 1, 2014 and December 31, 2015 and medical records examined for timing of garment ordering, delivery and fitting.

RESULTS

The majority believed that compression therapy is beneficial. Most centers reported using custom-fit and pre-fabricated garments, and a goal time of application between 2-4 weeks (42%) and 4-6 weeks (36%). After the garments are ordered, 61% of centers estimate that it takes 2-4 weeks for them to arrive. No significant differences in practices were found among centers treating pediatric patients only, adults only or both. Locally, the mean number of weeks between the date of original injury and garment order placement was 9.1 weeks with an additional 8.7 weeks between the date of order and date of delivery.

CONCLUSIONS

The current study identified that although the national reporting of time to garment application is estimated to be between 2-6 weeks at the majority of burn centers including our own, we found our center to be well in excess of 17 weeks. The findings offer an opportunity for local improvement, and raise the possibility of similar incongruity between goals and practice at other centers.

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.

Pressure garments for use in the treatment of hypertrophic scars—a review of the problems associated with their use

Pressure garments have been the mainstay of hypertrophic scar treatment since the 1970s. However, there are many problems associated with their use. This is the first in a series of papers on pressure garments that will review the literature published to date on the origins of pressure garments for hypertrophic scar treatment and the problems associated with current pressure garment use.

Effects of pressure exerted on the skin by elastic cord on the core temperature, body weight loss and salivary secretion rate at 35 degrees C

Effects of pressure exerted on the skin by elastic cord on the core temperature, body weight loss and salivary secretion rate were studied under conditions of ambient temperature of 35 degrees C and a relative humidity of 60%. Twelve healthy females, aged 18-23 years, served as subjects. The subjects entered a bioclimatic chamber and rested quietly in a chair for 80 min. Then, skin pressure was exerted by applying elastic cord (8.5 mm wide) to six different skin areas, such as axilla, under-bust, waist, inguines, thighs and ankles. The values of skin pressure by elastic cord ranged from 11.9 to 33.3 g/cm(2). In the control experiment, wrapping with an elastic cord was loosely performed without any skin pressure. Rectal and skin temperatures, body weight loss by sweating and salivary secretion rate were measured throughout the 160 min experimental period. Core temperature increased more significantly under pressure exerted on the skin. Body weight loss by mainly sweating and salivary secretion rate were significantly suppressed under pressure exerted on the skin. We discussed the physiological mechanisms in terms of suppression of central nervous activity as to why significant increase of core temperatures, inhibition of body weight loss mainly by sweating and of salivary secretion rate occurred, and furthermore practical significance of these findings for impairment of digestion, swallowing, vocalizing, defense against disease bacteria and sport activity.

Effects of clothing pressure caused by different types of brassieres on autonomic nervous system activity evaluated by heart rate variability power spectral analysis

The present study was designed to investigate the effects of clothing skin pressures exerted by two different types of brassieres (a conventional higher skin-pressured brassiere and a newly devised low skin-pressured brassiere) on the autonomic nervous system (ANS) activity. Six healthy young women (22.8 +/- 1.4 yrs.) with regular menstrual cycles participated in this study. The ANS activities were assessed by means of heart rate variability power spectral analysis. The skin pressures exerted by the brassieres were measured with an air-pack type contact surface pressure sensor at five different points. The total amount of clothing pressure, and the pressures at the center and the side regions of the brassieres were significantly greater in the high than in the low skin-pressured brassiere (Total 9816.1 +/- 269.0 vs. 6436.8 +/- 252.4 Pa, P < 0.01; Center 2212.1 +/- 336.3 vs. 353.8 +/- 85.8 Pa, P < 0.01; Side 2556.8 +/- 316.1 vs. 1747.2 +/- 199.2 Pa, P < 0.05). Concerning the ANS activity, the Total power, and the very low frequency (VLF) and the high frequency (HF) components were significantly decreased in the high skin-pressured brassiere than those in the low skin-pressured brassiere (Total 531.6 +/- 57.3 vs. 770.5 +/- 54.2 ms2, P < 0.01; VLF 60.7 +/- 14.6 vs. 179.2 +/- 38.1 ms2, P < 0.05; HF 209.5 +/- 33.2 vs. 283.2 +/- 61.5 ms2, P < 0.01). Our data indicate that the higher clothing pressures exerted by a conventional brassiere have a significant negative impact on the ANS activity, which is predominantly attributable to the significant decrease in the parasympathetic as well as the thermoregulatory sympathetic nerve activities. Since the ANS activity plays an important role in modulating the internal environment in the human body, excess clothing pressures caused by constricting types of foundation garments on the body would consequently undermine women's health.