• The Journal of Korean Physical Therapy
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• v.35 no.6
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• pp.206-212
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• 2023

Purpose: This study aimed to compare the lasting effects of the flossing band technique, dynamic and static stretching on hamstring on range of motion (ROM), muscle activity, and proprioception to identify the most effective pre-exercise method for preventing injuries. Methods: Thirty participants were randomly assigned to the flossing band (FB), dynamic stretching (DS), and static stretching (SS) groups, with 10 subjects in each. Measurements included muscle activity of the biceps femoris vis surface electromyography, knee ROM and proprioception during active knee extension and flexion using a smart joint goniometer. Assessments were conducted before, immediately after, 15, and 30 minutes after each intervention. Results: Proprioception showed no significant differences among groups at any time point. Significant differences in knee ROM were observed in the FB group (except between 15 and 30 minutes after), DS group (except between immediately after and 15 minutes after, and between 15 and 30 minutes after), and SS group (except between before and 15 minutes after, and between before and 30 minutes after). Muscle activity in the FB (except between before and 30 minutes after, and between 15 and 30 minutes after) and SS (between before and immediately after, between immediately after and 30 minutes after, and between 15 and 30 minutes after) groups showed significant differences, while the DS group exhibited no significant changes. Conclusion: Although direct comparisons did not establish superiority, within-group analyses indicated that the flossing band technique exhibited longer-lasting effects than dynamic and static stretching, providing valuable insights for injury prevention program design.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.28 no.3
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• pp.33-40
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• 2022

Background: The cross-body and the sleeper stretches have been used to improve posterior shoulder tightness (PST). However, such stretching techniques may not always help achieve scapular stability and may even aggravate patient's symptoms. Therefore, a new stretching technique (passive glenohumeral internal rotation with bridging) was developed as a more effective method that may allow for greater scapular stability without aggravating the symptoms. Thus, this study aimed to examine and compare this novel stretching technique to determine its effect on the range of motion (ROM) and acromio-humeral distance (AHD) in patients with glenohumeral internal rotation deficits (GIRD) with posterior shoulder tightness. Methods: A total of 30 symptomatic patients with asymmetrical GIRD were randomly assigned to two groups: the novel stretching group (n=15) and the joint mobilization group (n=15). The intervention was conducted twice a week for a total of four weeks. The ROM of shoulder internal rotation was measured by a goniometer and the AHD was evaluated by an X-ray before and after the intervention. Results: Both the treatments improved ROM and AHD in patients with GIRD (p<.05). However, the improvements in internal rotation ROM and AHD in the novel stretching group were significantly greater than that of the subjects in the mobilization group. There was a significant difference between the two groups (p<.05). Conclusion: These results show that both novel stretching and joint mobilization improved ROM and AHD in patients with GIRD with PST. However, novel stretching was more effective than joint mobilization.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.2
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• pp.193-198
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• 2010

In this paper, an efficient contrast enhancement algorithm using histogram stretching is proposed. Histogram equalization (HE) and histogram stretching (HS) are effective techniques for contrast enhancement. However, HE and HS result often in excessive contrast enhancement. Proposed technique not only produces better results than those of conventional contrast enhancement techniques, but is also adaptively adjusted to image contents.

• Advances in concrete construction
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• v.15 no.5
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• pp.349-358
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• 2023

Aim of this work is investigating effect of thickness-stretching formulation on the quasi three-dimensional analysis of micro plate based on a thickness-stretched and shear deformable model through principle of virtual work and micro-scale dependent constitutive relations. Governing differential equations are derived in terms of five unknown functions and the analytical solution is derived using Navier's technique. To explore effect of thickness stretching model on the static results, a comparison between the results with and without thickness stretching effect is presented.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.77-87
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• 2023

PURPOSE: The purpose of this study was to investigate the changes in the flexibility and elasticity of the muscles when the hamstrings were stretched in one direction and when they were stretched in three directions. METHODS: In this study the subjects were divided into two groups, namely the 'one-direction stretching exercise of the hamstring muscle in the neutral position' group (female: 14 people, male: 14 people) and the 'three-way stretching exercise' group (female: 12 people, male: 14 people) considering the positions of the three hamstring muscles. The elasticity and flexibility of the hamstring muscles were measured before and after the self-extension exercise, and the average value of two measurements was noted. To evaluate the flexibility of the hamstring muscle, a 'sit and reach' test was performed, and muscle elasticity was measured using the MyotonPRO® device. RESULTS: After the stretching exercise, flexibility increased in both groups. In terms of muscle elasticity, the body dynamic strength and resonance frequency of the stretching one-direction stretching group decreased after the stretching exercise. CONCLUSION: To alter the muscle characteristics and increase the flexibility when performing a stretching exercise, selecting and stretching only one muscle with the lowest range of motion yields effective results. The ideal technique to be employed appears to be to stretch the entire hamstring muscle in one direction from the neutral position.

• Physical Therapy Korea
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• v.27 no.1
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• pp.30-37
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• 2020

Background: To prevent or reduce the risk of strain injury, various approaches, including stretching techniques are currently being used. The effect of proprioceptive neuromuscular facilitation (PNF) and static stretching on flexibility has been demonstrated; however, it is not clear which one is superior. Objects: This study aimed to evaluate the differences between the effects of PNF and static stretching performed at various intensities on muscle flexibility. Methods: The maximum voluntary isometric contraction (MVIC) of the hamstrings using the PNF stretching technique was performed in the P100 group, while 70% of the MVIC was performed in the P70 group. The MVIC value obtained during the PNF stretching in both groups was used as a reference for setting the intensity of static stretching. Static stretching was performed at 130% (S130), 100% (S100), and 70% of the MVIC (S70). The active knee extension (AKE) values, defined as the knee flexion angle were measured before stretching (baseline), immediately after stretching (post), and at 3 minutes, 6 minutes, and 15 minutes. Results: PNF stretching produce a greater improvement in flexibility compared with static stretching. Specifically, the ΔAKE was significantly higher in the S100 and S70 groups than in the P100 group at Post. In the comparison of ΔAKE over time in each group, the ΔAKE at Post showed a significant decrease compared to the value at Baseline in the S130 group; however, no significant difference was observed at 6 minutes while a significant increase was noted at 15 minutes. Conclusion: This study found that PNF stretching is more effective than static stretching with respect to increasing and maintaining the flexibility of muscles. In addition, the increase in flexibility at maximal intensity was similar to that observed at submaximal intensity during both PNF and static stretching.

• Journal of Naturopathy
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• v.11 no.2
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• pp.152-157
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• 2022

Background: There have been no reports of studies on the effect of a combination of myofascial relaxation technique and passive stretching on the lower extremity body shape of working women. Purpose: This study aimed to examine the effects of myofascial relaxation technique and passive stretching on body composition and body composition analysis (intracellular fluid, skeletal muscle mass, body cell mass), etc. Methods: The subjects of this study were 30 women at a body shape management center who had many problems with their subjective lower extremity body shape. Fifteen subjects were in the experimental group and the control group. The experimental group applied the fascial relaxation technique twice a week for nine weeks. The control group conducted stretches by themselves at least twice a week according to the active stretching instructions. The ANOVA program analyzed the data. Results: In the experimental group, intracellular fluid (p < .05), skeletal muscle mass (p < .048), and body cell mass (p < .047) were significantly increased. Conclusion: The lower extremity edema of working women decreased

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.69-79
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• 2024

PURPOSE: This study compared the effect of the muscle energy technique (MET) and stretching technique on ankle dorsiflexion passive range of motion, balance, and gait ability of stroke patients with limited ankle dorsiflexion. METHODS: Forty-four post-stroke patients participated. The participants were randomized into the MET group (METG; n = 22) and the stretching group (STG; n = 22). The METG was subjected to the MET to relax the dorsiflexion, while the STG was subjected to the dorsiflexion stretching technique. Both groups completed standard neurological physical therapy for 30 min per session. The intervention was conducted five times a week over 3 weeks for a total of 15 times. All participants underwent ankle dorsiflexion passive range of motion measurement and Berg Balance Scale score determination and completed a 10-m walking test and the timed up and go test before and after the intervention. RESULTS: After the 3-week intervention, both groups showed significant improvement after the intervention (p < .05). METG participants showed greater improvements in ankle dorsiflexion passive range of motion and 10-m walking test results compared to STG participants (p < .05). CONCLUSION: Both interventions improved ankle dorsiflexion passive range of motion, balance, and gait ability in stroke patients with limited ankle dorsiflexion. Moreover, the MET was superior to ankle dorsiflexion passive range of motion on the 10-m walking test.

• 한국전산유체공학회:학술대회논문집
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• 2000.05a
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• pp.159-165
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• 2000

In this paper, numerical study has been done for the improvement of the superdetonative ram accelerator performance and for the design optimization of the system. The objective function to optimize the premixture composition is the ram tube length required to accelerate projectile from initial velocity $V_o$ to target velocity $V_e$. The premixture is composed of $H_2,\;O_2,\;N_2$ and the mole numbers of these species are selected at design variables. RSM(Response Surface Methodology) which is widely used for the complex optimization problems is selected as the optimization technique. In particular, to improve the non-linearity of the response and to consider the accuracy and efficiency of the solution, design space stretching technique has been applied. Separate sub-optimization routine is introduced to determine the stretching position and clustering parameters which construct the optimum regression model. Two step optimization technique has been applied to obtain the optimal system. With the application of stretching technique, we can perform system optimization with a small number of experimental points, and construct precise regression model for highly non-linear domain. The error to compared with analysis result is only $0.01\%$ and it is demonstrated that present method can be applied more practical design optimization problems with many design variables.

• Journal of computational fluids engineering
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• v.5 no.2
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• pp.55-63
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• 2000

In this paper, the numerical study has been done for the improvement of the superdetonative ram accelerator performance and for the design optimization of the system. The objective function to optimize the premixture composition is the ram tube length, required to accelerate projectile from initial velocity V/sub 0/ to target velocity V/sub e/. The premixture is composed of H₂, O₂, N₂ and the mole numbers of these species are selected as design variables. RSM(Response Surface Methodology) which is widely used for the complex optimization problems is selected as the optimization technique. In particular, to improve the non-linearity of the response and to consider the accuracy and the efficiency of the solution, design space stretching technique has been applied. Separate sub-optimization routine is introduced to determine the stretching position and clustering parameters which construct the optimum regression model. Two step optimization technique has been applied to obtain the optimal system. With the application of stretching technique, we can perform system optimization with a small number of experimental points, and construct precise regression model for highly non-linear domain. The error compared with analysis result is only 0.01% and it is demonstrated that present method can be applied to more practical design optimization problems with many design variables.