• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.282-292
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• 2000

A meta-analysis of 14 quasi-experimental studies was conducted to compare the effect of size on various relaxation therapies applied to patients and health volunteer students. These studies were selected from theses, dissertations and papers that have been done between 1982 to 1993. Also They have a randomized or nonequivalent control group in a pre test-post test design. The studies were evaluated in different ways; 1) types of relaxation therapy, 2) total amount of time of relaxation therapy, and 3) types of outcome variables. For a group of homogenious studies, the weighted mean effect size and standard error were estimated. Some findings are summarized as follows : 1. Jacobson relaxation therapy had a larger effect on systolic and diastolic blood pressures than on state anxiety. 2. For the total time of relaxation therapy, (longer than 60 minutes) had a much larger effect in decreasing systolic and diastolic blood pressures than in the case of a time period shorter than 60 minutes. 3. Relaxation therapy applied to surgery patients also had a larger effect in decreasing state anxiety than when applied to other patients.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.279-289
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• 1995

This study was designed 1) to develop a hypertensive animal model in which the blood pressures (BPs) of symmetric regions (right and left upper extremities) are significantly different and 2) to test the effect of BP per se on the contractility and endothelium-dependent relaxation of vascular smooth muscle. Rabbits were anesthetized with sodium pentobarbital and ventilated with room air via animal respirator. The transverse aorta was exposed through the left second intercostal space and the lumen of the aorta was narrowed partially by ligation using 3-0 silk and a probe at a point between the origins of the brachiocephalic trunk and the left subclavian artery. Four to eight weeks postoperatively, BPs were measured in the carotid artery as the high BP area (proximal to coactation site) and in the femoral artery as the low BP area (distal to coarctation site). In the animal model, pressure-overload hypertension was developed and the BP of the right subclavian artery was higher than that of the left subclavian artery. The concentrations of circulating epinephrine, norepinephrine, angiotensin I, and angiotensin II were measured. The right and left subclavian arteries and their branches were used for isometric tension recording in organ baths and their responsiveness to phenylephrine, serotonin, acetylcholine, and sodium nitroprusside were examined. The BPs of carotid and femoral artery in control animals were $116{\pm} 12/75{\pm}9\;mmHg (mean ${\pm}SEM$) and $130{\pm}16/68{\pm}9\;mmHg$ respectively, while those of carotid and femoral artery in the hypetensive animals were $172{\pm}6/111{\pm}10\;mmHg$ and 136{\pm} 4/100 {\pm}9\;mmHg$ respectively. There were no significant differences in the concentrations of circulating epinephrine, norepinephrine, angiotensin I, and angiotensin II between controls and the animal models. No significant differences were found in the vascular sensitivities to phenylephrine and serotonin between the high pressure-exposed vessels and the low pressure-exposed vessels. However, the endothelium-dependent relaxation to acetylcholine and nitroprusside-induced relaxation showed significant differences between the high pressure-exposed and the low pressure-exposed subclavian arteries. From the above results, we suggest that the contractility of vascular smooth muscle is unchanged by the elevated pressure per se. However, the endothelium-dependent relaxation to acetylcholine and the nitroprusside-induced relaxation are attenuated by pressure.

• Journal of Biomedical Engineering Research
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• v.26 no.2
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• pp.87-93
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• 2005

A new method for real-time estimating left ventricular relaxation time constant (T) from the left ventricular (LV) pressure waveform, based on the isovolumic relaxation model, is proposed. The presented method uses a recursive least squares (RLS) algorithm to accomplish real-time estimation. A new criterion to detect the end-point of the isovolumic relaxation period (IRP) for the estimation of T is also introduced, which is based on the pattern analysis of mean square errors between the original and reconstructed pressure waveforms. We have verified the performance of the new method in over 4,600 beats obtained from 70 patients. The results demonstrate that the proposed method provides more stable and reliable estimation of τ than the conventional 'off-line' methods.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.111-115
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• 2004

In this paper, evaluation of physical properties about dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DLPC, DMPC using pressure stimulus. As a result, the changed surface pressure, displacement current and the transition forms of dipole moment of phospolipid monomolecular in area per molecular by pressure stimulus were conformed well. It was known that the monolayers by linear relationship for decision of dielectric relaxation time between compressure speed $\alpha$ and molecule area $A_m$ By according to the linear relationship relation get that frictional constant $\xi$, DLPC was $1.89{\times}10^{-19}$[Js] and DMPC was $0.722{\times}10^{-19}$[Js]. It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.3
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• pp.38-50
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• 1988

carried out to present a rheology model which is able to treat time-dependent properties of clay. The results were summarized as follow ; 1. The slope (a(e1)) of deviator stress in strain rate test was independent on axial strain, and pore water pressure was decreased with increment of strain rate. 2. The pore water pressure in a stress relaxation condition was not changed when the strain rate before stress relaxation was 0.05%/min., but it was increased with increment of time when the strain rate before stress relaxation was 0.2%/min 3. The greater the stress condition (q/qmax) and the strain rate before creep test became, the greater the increment rate of axial strain in creep test became. 4. SEKIGUCHI's constitutive equation was slightly overpredicted while empirical equation proposed in the study was well coincided with measured values. 5. The constitutive equation induced by a strain function could be dealed with a behavior of the pore water pressure increased with increment of elapsed time after primary consolidation.

• The Journal of the Acoustical Society of Korea
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• v.15 no.4E
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• pp.72-77
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• 1996

A relatively simple theoretical model for predicting the shock thickness is applied to the weak shock propagation through sea water, where the boric acid and the magnesium sulfate are the major relaxation processes. The relaxation effects increases the shock thickness by the factor of 103 compared with the thickness based on the classical absorption only. In seawater with the ambient pressure of 125 atm and 15℃ temperature, the effects of the boric acid are dominant when the peak pressure is less than 0.3 atm and 3 atm. For the shocks of peak pressure greater than 5 atm, the effects of the classical absorption theory is enough to describe the shock thickness. The effects of the ambient pressure and temperature on the shock thickness are also evaluated.

• Journal of Korean Academy of Nursing
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• v.19 no.2
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• pp.191-202
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• 1989

This study was peformed to examine the effect of muscle relaxation training on patients with insomnia complaint. The subjects were selected those who have taken poor sleep below 240-300 minutes. per day, between 16-15ages, without organic brain syndroms. Using the Budzinski's muscle relaxation training tapes the patients have been gotten the muscle relaxation training daily during four weeks and examined the state anxiety with Spielberger's Trait-State Anxiety Scale, and investigated Sleep amounts, Blood pressure, Pulse rates, Respiratory rates before and after the muscle relaxation training. The results were as follow : 1. The mean of the State anxiety after the muscle relaxation training(41.8$\pm$6.4) was significantly lower than that of before training (54.2$\pm$7.0) (p＜0.001). 2. The mean of systolic blood pressure after the training (114.$\pm$7.8mmHg) was significantly lower than that of before training (139.0$\pm$9.8) (P＜0.001). 3. The mean of Pulse rate after the traing (89.2$\pm$3.0) was significantly lower than that of before training (103.9$\pm$7.4) (P＜0.001). 4. The mean of Respiratory rate after the training(18.6$\pm$1.0) was significantly lower than that of before training(22.8$\pm$1.3) (P＜0.001). 5. The mean of Sleep amount after the muscle relaxation training (459.8$\pm$52.4 minutes) was significantly increased than that of before training (287.3$\pm$30.3) (P＜0.001).

• PNF and Movement
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• v.13 no.4
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• pp.197-202
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• 2015

Purpose: This study aimed to examine the effects of a proprioceptive neuromuscular facilitation (PNF) program on neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio in a visual display terminal (VDT) worker. Methods: We recruited a 33-year-old VDT worker diagnosed with chronic VDT syndrome. The subject was treated using a PNF program for 20 minutes a day, three times a week for six weeks. All evaluations were performed every two weeks on the first test day. Results: The PNF program resulted in a significant improvement in the subject's neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio after six weeks, in comparison to the subject's condition before treatment. Conclusion: The PNF program can be used effectively to improve neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio in visual display terminal (VDT) workers.

• Physical Therapy Korea
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• v.28 no.1
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• pp.72-76
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• 2021

Background: A pressure ulcer is common in soft tissue over the greater trochanter (GT) in side-lying position, and sustained tissue deformation induced by the prolonged external force is a primary cause, which can be discussed with soft tissues' viscoelastic properties (i.e., stress relaxation, creep response). Objects: Using an automated hand-held indentation device, we measured the viscoelastic properties of soft tissue over the hip area, in order to examine how the properties are affected by site with respect to the GT. Methods: Twenty participants (15 males and 5 females) who aged from 21 to 32 were participated. An automated hand-held indentation device was used to measure the stress relaxation time and creep response. Trials were acquired for three different locations with respect to the GT (i.e., right over the GT, 6 cm anterior or posterior to the GT). For each location, five trials were acquired and averaged for data analyses. Results: Soft tissues' stress relaxation time and creep response were associated with site (F = 23.98, p < 0.005; F = 24.09, p < 0.005; respectively). The stress relaxation time was greatest at posterior gluteal region (19.22 ± 2.49 ms), and followed by anterior region (15.39 ± 2.47 ms) and right over the GT (14.40 ± 3.18 ms). Similarly, creep response was greatest at posterior gluteal region (1.16 ± 0.14), and followed by anterior region (0.95 ± 0.14) and right over the GT (0.89 ± 0.18). Conclusion: Our results showed that the stress relaxation and creep were greatest at the posterior gluteal region and least at right over the GT, indicating that the gluteal soft tissue is more protective to the prolonged external force, when compared to the trochanteric soft tissue. The results suggest that a risk of pressure ulcer over the GT may decrease with slightly posteriorly rotated side-lying position.

• Physical Therapy Rehabilitation Science
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• v.5 no.4
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• pp.178-184
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• 2016

Objective: Tension-type headache is caused by hormones, foods, irritants, stress, obesity, fatigue, and neck and head trigger points-prolonged abnormal posture. The purpose of this study was to evaluate the effects of relaxation approach on head posture, static postural stability, and headache in persons with tension-type headache. Design: Randomized controlled trial. Methods: Thirty-five persons with tension-type headache participated in this study. This study was a pretest-posttest with a control group design for a duration of 4 weeks (60 min/3 times/1 wk). The participants were randomly allocated to the relaxation approach group (n=18) and the control group with conventional rehabilitation including thermotherapy and transcutaneous electrical stimulation for the same period (n=17). Outcome measures involved forward head posture (FHP), foot pressure, neck disability index (NDI), and six-item headache impact test (HIT-6). Results: Relaxation approach and control groups improved significantly in the amount of forward head posture, neck disability index, and six-item headache impact test scores after training (p<0.05). The control group was found to be significantly different in the amount of FHP, backward foot pressure, NDI, and HIT-6 after training compared to before training (p<0.05). The relaxation approach group significantly improved in forward head posture, neck disability index, and six-item headache impact test compared with control group after training (p<0.05). Neck disability index and six-item headache impact test significantly improved after training compared with before training in the control group (p<0.05). However, the foot pressure was not significantly different between relaxation approach and control groups. Conclusions: This study suggests that treatment with relaxation approach combined with self-exercise would be effective in reducing the amount of forward head posture, neck disability and headache impacts.