• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.771-781
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• 2018

This study deals with free vibrations analysis with stretching effect of nanocomposite beams reinforced by single-walled carbon nanotubes (SWCNTs) resting on an elastic foundation. Four different carbon nanotubes (CNTs) distributions including uniform and three types of functionally graded distributions of CNTs through the thickness are considered. The rule of mixture is used to describe the effective material properties of the nanocomposite beams. The significant feature of this model is that, in addition to including the shear deformation effect and stretching effect it deals with only 4 unknowns without including a shear correction factor. The governing equations are derived through using Hamilton's principle. Natural frequencies are obtained for nanocomposite beams. The mathematical models provided in this paper are numerically validated by comparison with some available results. New results of free vibration analyses of CNTRC beams based on the present theory with stretching effect is presented and discussed in details. The effects of different parameters of the beam on the vibration responses of CNTRC beam are discussed.

• PNF and Movement
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• v.6 no.2
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• pp.11-18
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• 2008

Purpose : The purpose of this study was to identify that the effect of hold-relax and active stretching on recoveries of upper trapezius and sternocleidomastoid muscle fatigue after computer work. Methods : This study was conducted by 30 volunteer at the age of 23~33(resting group=10, hold-relax group=10, active stretching group=10). The muscle fatigue measured by tracing the median frequency(MDF) decrement from power spectrum analyses of EMG signals and the data were analyzed repeated ANOVA. Result : In case of upper trapezius, there was significant difference in group I,II and group II, III. In case of sternocleidomastoid, there was significant difference in group I,II and group I,III. Conclusion : The active stretching was effective for sternocleidomastoid and the hold-relax was effective for upper trapezius and sternocleidomastoid. The hold-relax was effective better than active stretching on recoveries of muscle fatigue.

• The Journal of Korean Physical Therapy
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• v.34 no.4
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• pp.181-186
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• 2022

Purpose: This study was to applied to stretching plantar flexor and invertor at the same time to observe the effect of balance and walking ability. Methods: Subjects were instructed patients with ankle limited of motion, 6 months after stroke. We classified 20 subjects into two groups (experimental group: stretching plantar flexor and invertor at the same time, control group: only stretching plantar flexor). each group included 10 subjects and applied ankle stretcher for 20 minutes, 5 times/week during 4 weeks (total 20 times). Results: Both experimental group and control group showed significant increases in static balance, however, the significantly increases in step length and gait speed was observed only in the experimental group. There was no significant increases in step length and gait speed in the control group. Conclusion: Simultaneous stretching of ankle invertor and plantar flexion is effective in improving balance and walking ability in chronic stroke patients.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.39-46
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• 2017

PURPOSE: The effectiveness of the stretching to increase the range of motion of the joint, reduce the risk of injury, enhance athletic performance or decrease post exercise muscle soreness. This study was to compare the effect of the stretching method applied on the shortened hamstring muscle for flexibility, strength, pressure pain threshold value and muscle tone. METHODS: This study is a two-group pretest- posttest design. Fifty-four healthy young adults were randomly assigned to a vibration-assisted stretching group (VASG, n=27) or a static stretching group (SSG, n=27). Participants performed each stretch in 4 sets of 30 seconds each. A 30-second break time was provided between the sets. The range of motion, strength, pressure pain threshold values and muscle tone of the hamstring muscle were measured to compare the effects of the stretching methods. RESULTS: Both the VASG and the SSG participants showed significant improvement in the range of motion and strength (p<.05); however, the increase in the VASG was significantly higher than that in the SSG (p<.05). The pressure pain threshold values and muscle tone were significantly decreased only in the VASG (p<.05). CONCLUSION: These findings indicate that vibration-supported stretching is an effective intervention for people with hamstring shortening, with high pain level and muscle tone decrease.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.9 no.2
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• pp.39-46
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• 2011

Purpose : The purpose of this study was to compare the effect of three types of therapeutic exercises by applying them to lower back pain patients. Methods : This program was conducted for 30 patients 30 to 55 years old, who visited a rehabilitation center due to lower back pain. We separated participants into three groups with different therapeutic exercises: one with lumbar stabilization exercises, another with stretching exercises, and the other with both exercises. Each exercise was held once a day, 3 days a week, for 6 weeks. We analyzed the effect of these exercises by checking the change of lumbar muscle strength and pain relief. Lumbar muscle strength was measured by AS-Med and pain strength was estimated by VAS. Results : The result of the programs was established according to the following list: 1) Lumbar stabilization exercises and stretching exercises lead to higher lumbar muscle strength and pain relief (p<0.05). 2) Lumbar muscle strength in the lumbar stabilization exercise group was significantly higher than the stretching exercise group (p<0.05). 3) Pain relief in the stretching exercise group was significantly higher than the lumbar stabilization exercise group (p<0.05). Conclusion : This study shows all of the groups experienced higher lumbar muscle strength and pain relief. Specifically, there was higher lumbar muscle strength in the lumbar stabilization exercise group and higher pain relief in the stretching exercise group. Therefore the ideal intervention to improve lumbar muscle strength and pain relief for patients is to implement both lumbar stabilization exercises and stretching exercises.

• Child Health Nursing Research
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• v.12 no.2
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• pp.196-203
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• 2006

Objectives: This study was conducted to test whether stretching helps high school students recover from their fatigue and improve concentration. Method: The method of this study adopted a nonequivalent control group with pre-test and post-test designs. The period of data collection was from November to December in 2004. The 135 subjects were randomly selected from two high schools in Ulsan : one school as control group(n=66) and the other school as an experimental group(n=69). The experimental group had stretching for 10 minutes before the start of their fifth period class, five times a week(once a day) 4weeks of period, but the control group did not do. Result: After stretching, the students' level of fatigue in the experiment group was immensely reduced (t=4.75, p<.001). After the stretching, the concentration level of the experimental group increased vastly compared to the control group (t=3.35, p≤.005). Conclusion: Stretching is useful to reduce fatigue and improve concentration of high school students. This study recommended that stretching, which is not limited by high physical techniques, or specific time or spaces would help high school students' health, since they do not exercise regularly and are tired physically and mentally.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.93-99
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• 2018

The purpose of this study was to prove the effect of passive stretching after delayed muscular pain induction in university students and to propose a rehabilitation exercise program for effective pain relief and prevention in case of injury. Subjects were divided into passive stretching group and control group. Passive stretching group was performed passive stretching after delayed muscular pain induction and control group did not perform any treatment after delayed muscular pain induction. The delayed muscular pain induction method was induced by bench step motion. The height of the step box was 50cm. The data were analyzed by two-way RGRM ANOVA for comparison of passive stretching group and control group. In conclusion, passive stretching after delayed myalgia has a positive effect on blood fatigue (CRP, LDH) and subjective pain scale(VAS).

• Transactions of Materials Processing
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• v.7 no.5
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• pp.459-464
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• 1998

Effect of the several initial textures such as random texture, rolling texture and cube texture, on the plane strain stretching was studied by interpretation of the finite element method. The calculation of yield locus indicated that the sheet oriented in the cube texture exhibits easy yielding on uniaxial stress state whereas the sheet having either a random or the rolling texture exhibits easy yielding on shear deformation. Upon stretching tests, the thickness strain at the center region contacting the punch was identical regardless of the initial textures while the dependence of the thickness strain on the initial texture was found in the other regions. In general punch loads required or the sheet with an initial cube texture was as expected from calculated yield locus, lower than those for the others.

• Structural Engineering and Mechanics
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• v.11 no.2
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• pp.185-197
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• 2001

This paper presents the effect of axial stretching on large amplitude free vibration of an extensible suspended cable supported at the same level. The model formulation developed in this study is based on the virtual work-energy functional of cables which involves strain energy due to axial stretching and work done by external forces. The difference in the Euler equations between equilibrium and motion states is considered. The resulting equations govern the horizontal and vertical motion of the cables, and are coupled and highly nonlinear. The solution for the nonlinear static equilibrium configuration is determined by the shooting method while the solution for the large amplitude free vibration is obtained by using the second-order central finite difference scheme with time integration. Numerical examples are given to demonstrate the vibration behaviour of extensible suspended cables.

• Journal of East-West Nursing Research
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• v.9 no.1
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• pp.25-34
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• 2004

This was one experimental study, conducted to identify the effects of stretching exercise included health education on physical health index, self-reported symptoms, and self-efficacy of exercise in Elderly. Subjects included 28 women elderly who were residents of H Dong, Dondae moon-Gu, Seoul. The treatment intervention was applied during total 8 weeks as 5 times/week for stretching exercise with 2 times/weeks for health education. Data collection were from February to April, 2004. SPSS Window program was used by aims of this study for data analysis. The results were as following: 1. 75 old age above (39.3%) was the most of age in subjects. None education (42.9%) was the most of subjects in this study. Perceived health state was the most as 71.4% in moderate and good health state. 2. Stretching exercise included health education, significantly effected on the total Cholesterol, HDL-cholesterol, triglyceride (p=.009*; p=.043*; p=.006*). However, the body fat weight was no significantly on the effect of stretching exercise included health education (p=.991). Also, stretching exercise included health education, significantly effected on total self-reported symptoms (p=.001*) with joint pain, joint rigidity, fatigue, indigestion, elimination disorder, and sleep disturbance. However, indigestion (p=.129) was no significantly on the effect of stretching exercise included health education. Self efficacy of exercise (p=.000*) was significantly on the effect. As according to this results, physical health index (total Cholesterol, HDL-cholesterol, triglyceride) and self-reported symptoms (joint pain, joint rigidity, fatigue, elimination disorder, and sleep disturbance) were reduced through stretching exercise included health education. Self efficacy was improved by this exercise program. Therefore, it is confirmed that stretching exercise included health education is an effective nursing intervention for physical, mental, and psychological health management in elderly. Accordingly, authors are proposing that variously effective health management exercise programs must be developed for elderly, at the same time, the application and following up on the programs will be more important in the future.