• The Journal of Korean Physical Therapy
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• v.32 no.4
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• pp.238-244
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• 2020

Purpose: This study compared the effects of the fascial distortion model (FDM), foam rolling (FR), and self-stretching (SS) on the ankle dorsiflexion range of motion (ROM). Methods: Thirty subjects who had no more than 30° of ankle dorsiflexion ROM at the weight-bearing lunge test were recruited in this study. They were divided into three groups: (FDM, FR, and SS), and underwent each intervention for five minutes. Before and after the intervention, the ankle dorsiflexion ROM in the supine (the open-) and standing (the closed-kinetic chain) of the subjects were tested. The changes in the ROM between pre- and post-intervention and among the groups were analyzed. Results: All groups showed increased ankle dorsiflexion ROM after the intervention in both positions. In the position of the open kinetic chain, the changes in the ROM between pre- and post-intervention had significant differences among the groups, and the FDM was higher than the FR and SS. In the position of the closed kinetic chain, the ROM after the interventions and the changes in the ROM had significant differences among the groups, and FDM was higher than the FR (ROM after the intervention, the change in ROM) and SS (the change in ROM). Conclusion: These findings showed that FDM had more efficiency than the FR and SS as FDM had a stronger effect on increasing ankle dorsiflexion in a short, limited time. Clinicians who have limited time to treat their patients, particularly trying to increase ankle dorsiflexion ROM, should consider the application of FDM.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.220-228
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• 2015

Objectives: The purpose of this study was to investigate estheticians' self-reported pain symptoms and pain levels according to the parts of the hand. Methods: Data were collected through a questionnaire survey among 116 estheticians from 31 skin care centers and spas. Information about general characteristics, job characteristics and work characteristics were based on data from the self-administered questionnaire. To determine the self-reported pain symptoms and pain levels according to the parts of the hand, a Cornell Musculoskeletal Discomfort Questionnaire was used. Results: The subjects had the greatest self-reported pain symptoms in the thumb(Right: 53.4%, Left: 46.6%) and felt the highest level of pain in the wrist(Right: 4.87 points, Left: 4.71 points). Physical burdens and age had statistically significant effects on the pain level in the right hand, while physical burdens and the manager rather than the director had statistically significant effects on the pain level in the left hand. Conclusions: Since the thumb and wrist have the greatest subjective pain symptoms in the hand, the use of proper tools is recommended in order to reduce the usage of the thumbs during massage, as is regular stretching to protect the wrists.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.79-86
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• 2022

Numerous fabrication techniques have been used to mimic cylindrical natural tissues, such as blood vessels, tendons, ligaments, and skeletal muscles. However, most processes have limitations in achieving the biomimetic properties of multilayered and porous architectures. In this study, to embrace both features, a novel self-assembly method was proposed using electrospun microfibrous sheets. A bilayer microfibrous structure, comprising two sheets with different internal stresses, was fabricated by electrospinning a polycaprolactone (PCL) sheet on a uniaxially stretched thermoplastic polyurethane (TPU) sheet. Then, by removing the stretching tension, the sheet was rolled into a hollow cylindrical structure with a specific internal diameter. The internal diameter could be quantitatively controlled by adjusting the thickness of the PCL sheet against that of the TPU sheet. Through this self-assembly method, biomimetic cylindrical structures with multilayer and porous features can be manufactured in a stable and controllable manner. Therefore, the resulting structures may be applied to various tissue engineering scaffolds, especially vascular and connective tissues.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.4
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• pp.1-9
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• 2020

PURPOSE: The current generation has shortened hamstrings due to a sedentary lifestyle, resulting in reduced flexibility of the hamstring and dysfunction. This study was undertaken to compare effects of three different release exercises on hamstring flexibility, in participants with short hamstrings. METHODS: Totally, 20 subjects having short hamstrings were involved in this study. The inclusion criterion for study participation was active knee extension test (AKET) less than 60°. All participants were subjected to 3 methods: hamstring foam roller release (HFRR), sitting self myofascial release (sitting SMR), and standing self myofascial release (Standing SMR). All participants randomly performed all three methods to avoid bias caused by learning or fatigue. Passive knee extension test (PKET), AKET, finger to floor distance test (FTFT), and pelvic tilting angle test (PTAT) were measured pre- and post-exercises. RESULTS: The PKET, AKET and FTFT were significantly increased after HFRR, sitting SMR, and standing SMR exercise (p < .05). However, PTAT was not significantly increased after the three exercises (p > .05). Furthermore, no significant differences were observed between PKET, AKET, FTFT and PTAT subsequent to HFRR, sitting SMR, and standing SMR (p > .05). CONCLUSION: Our results indicate that HFRR, sitting SMR and standing SMR were immediately effective in improving hamstring flexibility in participants with short hamstrings.

• Macromolecular Research
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• v.16 no.6
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• pp.539-543
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• 2008

Many natural proteins self-assemble in complex ways, either to fulfill their biological function or introduce particular properties, such as high strength and toughness. We report the morphological transition in water from a spherical to rod-like shape of Bombyx mori silk fibroin by reducing the pH. Transmission electron microscopy, scanning electron microscopy, and dynamic light scattering were used to characterize the dilute solutions of silk fibroin in an aqueous environment, and provide direct visualization of the transformation of spherical micelles at pH 6.8 to nanofibrils at pH 4.8. This change in morphology occurred as a result of the stretching entropy due to the formation of $\beta$-sheets, which was analyzed using circular dichroism spectroscopy. This study demonstrates the self-assembly of silk fibroin as a function of pH.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.49-49
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• 2010

Nanopiezotronics is an emerging area of nanotechnology with a variety of applications that include piezoelectric field-effect transistors and diodes, self-powered nanogenerators and biosystems, and wireless nano/biosensors. By exploiting coupled piezoelectric and semiconducting characteristics, it is possible for nanowires, nanobelts, or nanorods to generate rectifying current and potential under external mechanical energies such as body movement (handling, winding, pushing, and bending) and muscle stretching, vibrations (acoustic and ultrasonic waves), and hydraulic forces (body fluid and blood flow). Fully transparent, flexible (TF) nanogenerators that are operated by external mechanical forces will be presented. By controlling the density of the seed layer for ZnO nanorod growth, transparent ZnO nanorod arrays were grown on ITO/PES films, and a TF conductive electrode was stacked on the ZnO nanorods. The resulting integrated TF nanodevice (having transparency exceeding 70 %) generated a noticeable current when it was pushed by application of an external load. The output current density was clearly dependent on the force applied. Furthermore, the output current density depended strongly on the morphology and the work function of the top electrode. ZnO nanorod-based nanogenerators with a PdAu, ITO, CNT, and graphene top electrodes gave output current densities of approximately $1-10\;uA/cm^2$ at a load of 0.9 kgf. Our results suggest that our TF nanogenerators are suitable for self-powered TF device applications such as flexible self-powered touch sensors, wearable artificial skins, fully rollable display mobile devices, and battery supplements for wearable cellular phones.

• Physical Therapy Korea
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• v.30 no.3
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• pp.184-193
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• 2023

Background: Studies investigating the immediate effects of a single intervention to correct forward head posture are rare. Objects: This study aimed to compare the changes in treatment effects in patients with forward head posture and neck pain after manual and self-exercise therapy over a 1-hour period. Methods: Twenty-eight participants were randomly divided into manual and self-exercise therapy groups. Following the initial evaluation, manual or self-exercise therapy was applied to each group for 30 minutes each in the prone, supine, and sitting positions. The variables measured were the craniovertebral angle (CVA), stress level, pain level, and sternocleidomastoid (SCM) stiffness. After the intervention, re-evaluation was conducted immediately, 30 minutes later, and 1 hour later. Two-way analysis of variance (ANOVA) was used to compare the maintenance of treatment effects between the two groups. Results: Based on the two-way mixed ANOVA variance, there was no interaction between the groups and time for all variables, and no main effects were found between the groups. However, a significant effect of time was observed (p < 0.05). Post hoc tests using Bonferroni's correction revealed that in both groups, the CVA, pain, and stress showed significant improvements immediately after the intervention compared with before the intervention, and these treatment effects were maintained for up to 1 hour after the treatment (p < 0.0083) in the manual therapy group. However, the stress level was maintained until 30 minutes later (p < 0.0083) in the self-exercise group. There was no significant decrease in right SCM stiffness before and after the intervention; however, left SCM stiffness significantly decreased after the self-exercise intervention (p < 0.0083). Conclusion: Both manual and self-exercise therapy for 30 minutes were effective in reducing forward head posture related to the CVA, pain, and stress levels. These effects persisted for at least 30 minutes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5819-5828
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• 2015

This study was carried out to analyze how psychological anxiety factors perceived by sky divers at the time of sky diving affect self-confidence. To that end, a survey was executed on 150 sky divers and 123 questionnaires were selected for the final analysis with SPSS v.21. Major findings of the study are as follows: first, sky divers use stretching and breathing the most to cope with stress-related symptoms; second, psychological anxiety and self-confidence were different in religion, age and the number of sky diving; third, sky divers' psychological anxiety affects self-confidence negatively. This study will contribute to developing a program to help sky divers enhance psychological coping techniques to reduce anxiety while increasing self-confidence at the time of sky diving.

• The Journal of Korean Physical Therapy
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• v.35 no.4
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• pp.89-94
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• 2023

Purpose: This study investigates the impact of self-myofascial release using a foam roller on the quadriceps femoris for pelvic stability. We further compare the effects of a GRID surface Foam Roller (GFR), a Non-Vibration Foam Roller (NVFR), and a Vibration Foam Roller (VFR). Methods: Thirty healthy adults (15 males, 15 females) participated in this study and were randomly assigned to one of three conditions: GFR, NVFR, or VFR. Participants walked at self-selected speeds with an arm sling before and after foam roller stretching. The analyzed gait parameters included pelvic tilt, pelvic obliquity, and pelvic rotation. Results: In the NVFR and VFR groups, there was a Significant differences were obtained in the pelvic tilt between pre-test and post-test values (p<0.05) in the NVFR and VFR groups, but no significant difference was observed in the GFR group (p>0.05). Comparing the amount of change between the three groups exhibited a significant decrease in pelvic tilt in the NVFR and VFR groups compared to the GFR group (p<0.017). No significant differences were found in pelvic obliquity and pelvic rotation (p>0.05) in all groups. Conclusion: While walking, the use of a VFR for self-myofascial release results in pelvic alteration by reducing the anterior pelvic tilt. We propose that a foam roller can be utilized to enhance pelvic stability during gait.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.666-671
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• 1999

In this work, sulfonated poly(phenylene sulfide) (SPPS) was prepared by demethylation with aqueous NaOH solution after poly[methyl[4-(phenylthio)phenyl]sulfonium trifluoromethanesulfonate](PPST) was sulfonated with fumic sulfonic acid(10% $SO_{3}-H_{2}SO_{4}$). PPST soluble in organic solvents was synthesiszed by self-condensation polymerization of methyl-(phenylthio)phenyl sulfoxide(MPPSO). SPPS showed IR bands of asymmetric O=S=O stretching at $1200cm^{-1}$ and S-O stretching at $621cm^{-1}$ from $-SO_{3}H$ group. From the result, it could be known that sulfonic acid groups were introduced to poly(phenylene sulfide). when PPST was sulfonated for 12hr at $150^{\circ}C$, 1.48 sulfonic acid groups were introduced per repeat unit. The weight average molecular weight(Mw) of PPST and SPPS determined by high temperature GPC were 118323 and 131204, respectively. The SPPS exhibited adsorption capacity of ammonia gas $9.67mmol\;NH_{3}/g$ and it was much higher than that of active carbon or silica gel.