• Safety and Health at Work
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• v.12 no.4
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• pp.511-516
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• 2021

Background: Difficulties in walking and balance are risk factors for falling. This study aimed to predict dynamic balance based on demographic information and anthropometric dimensions in construction workers. Methods: This descriptive-analytical study was conducted on 114 construction workers in 2020. First, the construction workers were asked to complete the demographic questionnaire determined in order to be included in the study. Then anthropometric dimensions were measured. The dynamic balance of participants was also assessed using the Y Balance test kit. Dynamic balance prediction was performed based on demographic information and anthropometric dimensions using multiple linear regression with SPSS software version 25. Results: The highest average normalized reach distances of YBT were in the anterior direction and were 92.23 ± 12.43% and 92.28 ± 9.26% for right and left foot, respectively. Both maximal and average normalized composite reach in the YBT in each leg were negatively correlated with leg length and navicular drop and positively correlated with the ratio of sitting height to leg length. In addition, multiple linear regressions showed that age, navicular drop, leg length, and foot surface could predict 23% of the variance in YBT average normalized composite reach of the right leg, and age, navicular drop, and leg length could predict 21% of that in the left leg among construction workers. Conclusion: Approximately one-fifth of the variability in the normalized composite reach of dynamic balance reach among construction workers using method YBT can be predicted by variables age, navicular drop, leg length, and foot surface.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.88-93
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• 2020

Purpose: This study examined the inter-rater reliability of cervical proprioception, dynamic balance ability, and ankle dorsiflexion range of motion using STARmat^®, which is a practical clinical tool that can provide practitioners and patients with quantitative and qualitative results. Methods: Thirty healthy young subjects were enrolled in this study, and two well-trained physical therapists participated as a tester. Two testers measured the cervical joint position error at the starting position after neck flexion, extension, side bending, and rotation; three dynamic balance tests, including anterior excursion, anterior reaching with single leg balance, and posterior diagonal excursion; and ankle dorsiflexion range of motion using STARmat^®. The intra-class correlation coefficient (ICC) was used to determine the inter-rater reliability of the tests. Results: The inter-rater reliability for the cervical proprioception ranged from moderate to good (0.66 to 0.83), particularly for flexion (0.82), extension (0.70), right side bending (0.73), left side bending (0.71), right rotation (0.83), and left rotation (0.66). For the dynamic balance, the inter-rater reliability ranged from good to excellent (0.87 to 0.91), particularly for anterior excursion (0.86), posterior diagonal excursion (0.87 to 0.89), and anterior reaching with a single leg balance (0.90 to 0.91). In addition, for the ankle dorsiflexion range of motion, the ICC for the inter-rater reliability ranged from 0.95 to 0.96. Conclusion: STARmat^® is a reliable tool for measuring cervical proprioception, dynamic balance tests, and ankle dorsiflexion range of motion in healthy young adults.

• The Journal of Korean Physical Therapy
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• v.25 no.6
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• pp.405-410
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• 2013

Purpose: Most studies have reported that the abdominal muscle thickness differs according to gender but none of these studies reported a gender difference in the thickness of the multifidus and erector spine. The spinal alignment is affected by the left and right balance in the trunk muscle. The aim of this study was to identify the trunk muscle symmetry according to gender and the correlations of the trunk muscle thickness with spinal alignment. Methods: Forty three subjects(27 males and 16 females) were enrolled in this study. The trunk muscle thickness was measured by ultrasonography. The trunk muscle, which consisted of the rectus abdominis (RA), external oblique abdominis (EOA), internal oblique abdominis (IOA), transverse abdominis (TrA), erector spine (ES), and multifidus (MF), was measured. The spinal alignment was measured by Formetric-III 3D analysis. The dependent variables of the spinal alignment were the trunk imbalance, trunk inclination, lateral deviation, and surface rotation. Results: The muscle thickness of the EOA muscle increased more significantly in the right side than the left side (p<0.05). Each left and right difference in the muscle thickness between the male and female group showed a significant difference (p<0.05) except for the TrA thickness. Significant positive correlations were observed between the ES and lateral deviation and between the TrA with trunk imbalance. Conclusion: These results suggest that asymptomatic men have a greater trunk muscle thickness than women but there was no difference between the left and right in healthy adults. The trunk muscle thickness of ES, TrA is related by the spinal alignment.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.2
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• pp.57-67
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• 2003

Suppose that dental occlusion is related to body posture. We want to find out that improving occlusal balance may affect vibration and distribution of C.O.P. in which way, by measuring change of posture and center of gravity (center of pressure, C.O.P.) which plays important role in measuring balance sensation. Total 11 students at Kyung Hee dental college students, 4 females and 9 males (age: 23-30) participated in this test, who have normal occlusion (Angle's classification I), no TMJ problems. All of the participants have no tooth loss except 3rd molar, no prosthesis over single tooth restoration, no orthopedic problems which affect balance sensation, and no otorhinolaryngological problems. First, we registrated bite by centric relation, and then fabricated stabilization splint that is increased 3.5mm vertical dimension around premolar region. By F-scan (Tekscan Inc., Boston, Mass), we measured discrepancy of average contact pressure of left and right foot. And we also measured discrepancy of vibration of C.O.P(center of pressure). before setting stabilization splint and after wearing stabilization splint at intervals of 1 week, 2 weeks, 3 weeks after. In normal human beings, improved occlusal balance by stabilization splint leads to decrease of vibration of C.O.P. (P<0.05). One week after wearing stabilization splint, vibration of C.O.P. decreased reliably (P<0.05), two weeks after wearing stabilization splint, vibration of C.O.P. decreased similarly comparing to before wearing and one week after wearing. (P<0.05) After two weeks and three weeks, however, it was hard to find reliability. (P>0.05) Difference between average contact pressure of right and left foot also decreased. (P<0.05) We could find decrease after one week of wearing stabilization splint (P<0.05) and two weeks after, the decrease was more reliable than one week after. (P<0.05) After two weeks and three weeks, however, it was hard to find reliability. Improvement of occlusal balance leads to decrease of vibration of C.O.P. and decrease of difference between right and left average contact pressure.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.7 no.2
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• pp.5-22
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• 2001

The purpose of this study was to investigate the balancing training effect on weight bearing ratio and postural sway on the unstable surface for the CVA patients with balance disability. The inclusion criteria were walking independently 20m distances. Eighteen subjects, 4 with right and 14 with left hemiplegic patients were participated in this study. The range of age was from 35 to 75 and the duration from onset time was from 1 to 38 months. The intervention program including balancing training that they were introduced for 10 minutes every other day during 12 weeks to experimental group, and general therapeutic exercise to control group. The result of this study were as following; 1. The balancing training on the unstable surface showed that the postural sway of left/right distribution would appear more effective on sitting with eyes opened. 2. The balancing training on the unstable surface showed that the postural sway of forward/rear distribution, left/right distribution and distance would appear more effective on standing with eyes opened. 3. The balancing training on unstable surface would increase more effective on the weight-bearing ratio of left/right difference and frequency. 4. The balancing training on unstable surface was statistical significant on the postural sway of left/right distribution and area in experimental group. and it was statistical significant on the postural sway of forward/rear distribution, left/right distribution and distance in control group, too.

• PNF and Movement
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• v.15 no.3
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• pp.311-316
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• 2017

Purpose: Flatfeet are one of the risk factors of foot dysfunction and postural imbalance. The purpose of this study was to compare the limitation of stability (LOS) for the center of gravity (COG) between flatfeet and neutral feet on stable and unstable support surfaces. Methods: The study included 26 healthy, adult male participants: 14 with normal feet and 12 with flatfeet. The subjects were asked to incline the trunk maximumly to the left, right, anterior, and posterior directions and were asked to keep their feet on the floor with the knee extension. The subjects had 30 seconds of rest time between the tasks. The LOS (anterior, posterior, left, right) of COG was measured by Balance Trainer (BT4, Hur-labs, Tampere, Finland). An independent t- test was used to compare the LOS of COG between flatfeet and normal feet on stable and unstable support surfaces, respectively. Results: The LOS of the flatfeet group was generally decreased on stable support surfaces as compared to that of neutral feet, but it was not significantly different (p>0.05), while the LOS of the flatfeet group was significantly decreased compared to that of neutral feet on unstable support surfaces (p<0.05). Conclusion: This study suggested that the LOS of individuals with flatfeet may be decreased on unstable support surfaces and the postural balance of the flatfeet group may easily be disturbed on an unstable support surface.

• Current Applied Physics
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• v.18 no.11
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• pp.1368-1374
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• 2018

In this paper, forced vibration was used to regulate the droplet migration, fully recording the transient migration of droplets on a micro-textured substrate under the resonance frequency by a high-speed camera. The influence of resonance frequency and dynamic migration characteristics of droplets on the solid micro-texture surface under lateral vibration were researched. The experiment demonstrates that the driving force is caused by the difference between the left and right contact angles made the droplet oscillate and migrate, and as time t increases, the left and right contact points are periodically shifted and the amplitude of migration increases. Therefore, based on the droplet migration behavior and its force balance mechanism, a spring vibration model of migration behavior of the vibrating droplet micro unit was set up to predict the complete trajectory of its migration on a solid surface. The calculation results show that the theoretical displacement is less than the experimental displacement, and the longer the time, the larger the difference. Affected by the vibration, part of the droplet permeates through the micro-texture, resulting in the droplet losing height and the contact angle becoming smaller as well. While the other part of droplet overcomes the internal surface tension to migrate.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.3
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• pp.425-431
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• 2015

The objective of this study was to effect of Tai Chi on balance and muscle activity of ankle joints with USN sensor in elderly people. Thirty six elderly participated and randomly assigned to a experimental group with Tai Chi and control group. The experimental group trained using a Tai Chi through 3 times per a week over 6 weeks. For all subjects, their balance such as functional reach test and one leg stance test, the change of muscle activity of ankle joints with USN sensor wireless-electromyogram during leg closed stance with eye closed were measured, and the results were as followed. The results were of a signigicant changes to the balance in group and between group as well. Comparison of muscle activity left tibialis anterior and left gastrocnemius in group, there were significant difference. Comparison of muscle activity right tibialis anterior and right gastrocnemius in group, there were significant difference. Comparison of muscle activity between groups, there was significant difference. Additional results indicated that, elderly people who received Tai Chi in one study, improve balance control and muscle activity ankle joint. so it is anticipated that improvement in clinical utilization for the elderly who's gait ability and balance ability reduced.

• PNF and Movement
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• v.8 no.3
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• pp.27-37
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• 2010

Purpose : The aim of this study was to investigate the effects of stepper exercise using lower extremity patterns of PNF(Proprioceptive neuromuscular facilitation) on ankle muscle strength and balance ability of females in their twenties. Method : Twenty subjects participated in this experiment were carried out the exercise program dose of 5 days per week for 2 weeks. They were divided into two groups; using twist stepper group(lower extremity patterns of PNF group, n=10) and using straight stepper group(n=10). The effects of twist stepper and straight stepper were evaluated by measurements of normal standing(NSEO, NSEC), and dynamic type 1 and dynamic type 2, respectively. For each case, the experimental data were obtained about static balance in 3 items : mean X speed, mean Y speed and velocity moment, that of dynamic balance in 4 items : mean X speed, mean Y speed, time, distance. Results : The results of this study were as follows; 1) In straight stepper group, the statistically significants were significants were shown on right/left ankle muscle strength in case of dorsi-flexion. 2) In twist stepper group, the statistically significants were significants were shown on right/left ankle muscle strength in case of dorsi-flexion. 3) In straight stepper group, the statistically significants were significants were shown on right ankle muscle strength in case of plantar-flexion. 4) In twist stepper group, the statistically significants were significants were shown on right/left ankle muscle strength in case of plantar-flexion. Conclusion : The above results revealed that twist stepper exercise using lower extremity patterns of PNF was more effective than straight stepper exercise for improving the ankle muscle strength.

• Korean Journal of Applied Biomechanics
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• v.27 no.3
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• pp.211-217
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• 2017

Objective: The purpose of this study was to investigate the effect of a 12-week professional body massage program (PMP) on forward head posture, neck pain, and plantar foot pressure balance in men in their 20s. Method: A total of 20 men with musculoskeletal diseases were recruited for this study. The participants were asked to take part in a PMP twice a week for 12 weeks. The cranial vertical angle (CVA) for forward head posture and visual analogue scale (VSC) for neck pain and right/left foot plantar pressure balances were extracted to compare between pre- and post-program differences. Results: CVAs before ($56.86{\pm}4.55^{\circ}$) and after ($62.72{\pm}4.57^{\circ}$) and VSCs before ($6.95{\pm}1.70$) and after ($1.70{\pm}1.56$) PMP revealed statistically significant differences. The right foot, after PMP, showed a significant increase in the plantar pressure balance from $46.17{\pm}2.95$ to $49.44{\pm}1.29%$, while the left foot decreased significantly from $53.83{\pm}2.95%$ to $50.56{\pm}1.29%$. Therefore, based on these results, it may be said that the foot pressure balance abilities were improved after PMP because the ideal foot pressure ratio is 50%. Conclusion: Consequently, it was suggested that a 12-week PMP could be utilized for improvement of forward head posture, neck pain, and foot plantar pressure balance in men in the 20s with musculoskeletal diseases.