• Journal of Korean Physical Therapy Science
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• v.26 no.3
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• pp.57-69
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• 2019

Background: The purpose of this study was to compare and analyze the effects of neck and trunk combined exercise program and single exercise on neck angle and neck and shoulder muscle activity. Design: Randomized controlled trial. Methods: In the single exercise group, the basic stretching, head bending and neck bending exercises were performed. The neck and trunk combined exercise group performed torso strength and trunk stability exercises to stabilize the trunk, and then performed the same neck exercise as the single exercise group. The exercise program was conducted 5 days per week for 2 weeks. One-way repeated ANOVA was used to investigate the statistical analysis of neck angle, neck and upper and middle trapezius muscle activity. Results: 1) There was no significant difference in neck angle degree after exercise in neck single exercise group. 2) In the neck and trunk combined exercise, the neck angle degree decreased continuously with the increase of the experimental period and showed a significant difference. 3) In the single exercise group, the muscles which showed significant difference compared to the post-exercise were the right upper, left and right middle trapezius. 4) In the neck and trunk combined exercise group, the right neck muscles showed significant difference after the exercise before the experiment. Conclusion: It was found that the neck and trunk combined exercise was more effective in reducing neck angle and the muscle activity of the subjects with forward head posture was decreased and increased. However, both exercises showed positive effects.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.17-26
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• 2002

This study is aimed to compare the effect of visuo-perceptual biofeedback sitting balance training and conventional sitting balance training using Balance Master on stroke patients with that of program in order to analyze the effect it has on dynamic postural balance. The subjects are twenty-four stroke patients who are receiving physical therapy in Ilsan Paik Hospital and can maintain sitting posture by themselves. These patients were divided to control group and experimental group randomly. In order to compare to control and experimental group before and after the balance training, they were tested with Mann-Whitney U test and in order to compared the changes before and after the balance training, they were tested with Wilcoxon signed-ranks test. The results are as follows: we measured the ability of dynamic posture balance control with limit of stability(LOS) test and rhythmic weight shift test. There was an increasing improvement in the ability of dynamic posture balance control of the experimental group that had visuo-perceptual biofeedback sitting balance control training using the Balance Master(p<0.05, p<0.01). According to the results from above, compared to conventional sitting balance training programs, visuo-perceptual biofeedback sitting balance control training using the Balance Master is considered to be a more valuable therapy in balance control improvement and physical function improvement. It is considered that if the weak points are made up, the training with Balance Master will give help to stroke patients and to patients with balance control disabilities and will further more contribute to successful rehabilitation therapy.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.180-189
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• 2014

For a autonomous parking of unmanned car, this paper proposes a posture regulation algorithm of a car-like mobile robot, which is supported by a docking formation and a feedback linearization control law. Unlike the previous researches based on a path-planning and optimization algorithms, the autonomous car implemented the proposed autonomous parking algorithm can be parked without much computational burden and a high performance processor. Stability of the proposed docking formation and feedback linearization control law are analyzed and performance of the proposed algorithm is shown by implementing to the simulations with six scenarios and an actual car in the experiment place.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.119-127
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• 2014

This study tried to develop a basis for quantitative index of working postures associated with WMSDs (Work-related Musculoskeletal Disorders) that could overcome realistic restriction during application of typical checklists for WMSDs evaluation. The baseline data(for a total of 603 jbs) for this study was obtained from automobile manufacturing company. Specifically, data for back posture was analyzed in this study to have a better and more objective method in terms of job relevance than typical methods such as OWAS, RULA, and REBA. Major statistical tools were clustering, logistic regression and so on. The main results in this study could be summarized as follows; 1) The relationship between working posture and WMSDs symptom at back was statistically significant based on the results from logistic regression, 2) Based on clustering analysis, three levels for WMSDs risk at back were produced for flexion as follows: low risk(< $18.5^{\circ}$), medium risk($18.5^{\circ}{\sim}36.0^{\circ}$), high risk(> $36.0^{\circ}$), 3) The sensitivities on risk levels of back flexion was 93.8% while the specificities on risk levels of back flexion was 99.1%. The results showed that the data associated with back postures in this study could provide a good basis for job evaluation of WMSDs at back. Specifically, this evaluation methodology was different from the methods usually used at WMSDs study since it tried to be based on direct job relevance from real working situation. Further evaluation for other body parts as well as back would provide more stability and reliability in WMSDs evaluation study.

• Physical Therapy Korea
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• v.13 no.4
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• pp.39-46
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• 2006

The purpose of this study was to determine the effects of slump sitting postures on the masticatory, neck, shoulder, and trunk muscles associated with work-related musculoskeletal disorders (WRMD). Eleven healthy adults (age, $23.3{\pm}2.7$ yrs; height, $174.0{\pm}4.1$ cm; weight, $61.4{\pm}6.6$ kg) participated in this study. The participants were free of injury history and neurologic deficits in the masticatory, neck muscles and upper extremities at the time of participation. The subjects were asked to perform erect and slump sitting postures under the guidance of physical therapists. The surface electromyography (EMG) was recorded from the anterior temporalis, masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique, gluteus maximus muscles of 11 adults as they performed visual terminal display work, which are known as the weakened and tightened muscles owing to WRMD. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The results of study were as follows: The masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique muscles significantly differed in the slump sitting posture (p<.05). The muscle activities of the serratus anterior, middle trapezius muscle, and external abdominal oblique were significantly lower and that of the masseter, upper trapezius, L3 paraspinal muscles were significantly higher. Further research is needed to assess the motor control problems and the function of the deep muscles in posture stability of patients with WRMD.

• Safety and Health at Work
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• v.7 no.1
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• pp.49-54
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• 2016

Background: Prolonged sitting leads to low back discomfort and lumbopelvic muscle fatigue. This study examined the characteristics of body perceived discomfort and trunk muscle fatigue during 1 hour of sitting in three postures in office workers. Methods: Thirty workers sat for 1 hour in one of three sitting postures (i.e., upright, slumped, and forward leaning postures). Body discomfort was assessed using the Body Perceived Discomfort scale at the beginning and after 1 hour of sitting. Electromyographic (EMG) signals were recorded from superficial lumbar multifidus, iliocostalis lumborum pars thoracis, internal oblique (IO)/transversus abdominis (TrA), and rectus abdominis muscles during 1 hour of sitting. The median frequency (MDF) of the EMG power spectrum was calculated. Results: Regardless of the sitting posture, the Body Perceived Discomfort scores in the neck, shoulder, upper back, low back, and buttock significantly increased after 1 hour of sitting compared with baseline values ($t_{(9)}=-11.97$ to -2.69, p < 0.05). The MDF value of the EMG signal of rectus abdominis, iliocostalis lumborum pars thoracis, and multifidus muscles was unchanged over time in all three sitting postures. Only the right and left IO/TrA in the slumped sitting posture was significantly associated with decreased MDF over time (p = 0.019 to 0.041). Conclusion: Prolonged sitting led to increased body discomfort in the neck, shoulder, upper back, low back, and buttock. No sign of trunk muscle fatigue was detected over 1 hour of sitting in the upright and forward leaning postures. Prolonged slumped sitting may relate to IO/TrA muscle fatigue, which may compromise the stability of the spine, making it susceptible to injury.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.4
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• pp.141-150
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• 2022

PURPOSE: This study was conducted to investigate the effects of non-elastic and elastic tapes on pain, craniovertebral angle, and balance in forward head posture (FHP) patients. METHODS: A total of 44 adults with FHP were randomly assigned to a group that performed a stretching exercise after non-elastic taping (n = 22) and another group that performed the stretching exercise after elastic taping (n = 22), respectively. The stretching exercise was performed five times a week for 30 minutes per session. The visual analogue scale was used to compare neck pain, the craniovertebral angle was measured to compare alignment, and the limit of stability was measured to compare balance. RESULTS: The groups that performed the stretching exercise after both elastic and non-elastic taping showed significant positive changes in pain and the craniovertebral angle of the head in pre- post measurements (p < .05). In the follow-up test for the pain and craniovertebral angle, there was no significant difference from the post-test in the non-elastic group (p > .05), but a significant difference was seen in the elastic group (p < .05). CONCLUSION: Stretching exercises with taping for patients with a FHP are more effective in improving pain and alignment. However, the short-duration tape application did not affect the balancing ability. When the non-elastic tape was used, the effect lasted longer than that of the elastic tape, and pain relief was effective in the case of the elastic tape. Therefore, tape therapy would be more effective if customized according to the patient's condition.

• Physical Therapy Korea
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• v.30 no.1
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• pp.23-31
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• 2023

Background: Several factors contribute to shoulder pain, including abnormal neck posture, repeated use of the upper limbs, work involving raising the upper limbs above the head, and the effects of vibration. However, previous study has reported that constant vibration exposure could impact improvement of the stability on joints related with muscle recruitment and activation. For this difference reason, we need to verify for the complex study of relationship with repetitive upper limb movements, poor head posture, and constant vibration exposure. Objects: Our study was made to investigate the influence of vibration exposure on the shoulder muscle activity during forward-head and over-head tasks with isometric shoulder flexion. Methods: In a total of 22 healthy subjects, surface electromyography (EMG) data were collected from shoulder muscles (upper/lower trapezius, serratus anterior, and lumbar erector spinae) on tasks (neutral-head task [NHT], forward-head task [FHT], and over-head task [OHT]) with and without vibration exposure. Results: In all tasks, the EMG data of the upper trapezius and serratus anterior significantly increased with vibration exposure (p < 0.05). Furthermore, the EMG data of the lumbar erector spinae significantly increased with vibration exposure in the NHT and FHT (p < 0.05). Conclusion: We suggest that continuous vibration exposure during the use of hand-held tools in the tasks could be associated with harmful effects in the workplace. Lastly, we clinically need to examine the guidelines regarding the optimal posture and vibration exposure.

• Journal of Korean Physical Therapy Science
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• v.17 no.1_2
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• pp.23-32
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• 2010

Purpose: The purpose of this study was to investigate trunk and gluteal muscle activation during one-leg standing or two-leg standing with lumbar stabilizing taping using non-elastic tape. Method: The subjects of this study were twenty subjects(man=11, women=9) who be in good physical health and have not problem to back muscle and one leg standing. The surface electromyographic(EMG) data were recorded on external oblique(EO), gluteus medius(GMed), gluteus maximus(GMax), quadratus lumborum(QL) while pre- and post-lumbar stabilizing taping in two-leg standing and one-leg standing. The analysis of data was performed using the paired samples t-test to compare the difference of EMG activity of pre and post lumbar stabilizing taping. Result: Contrast of pre-lumbar stabilizing taping the muscle activity of QL in post-lumbar stabilizing taping is significant decrease on two-leg standing posture(p<.05), and the muscle activity of GMed is significant increase on one-leg standing posture(p<.05). Thus, we suggest that lumbar stabilizing taping using by functional tape will be able to affect on lumbar stability and gluteal muscle retraining.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.915-916
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• 2015

The main sensor of AGV is the guide sensor in order to detect the path, and the sensor consists of 8 or 16-magneto resistance devices arranged by with 10mm. In controlling the AGV posture by using the sensor, AGV is occurred left/right shaking frequently. So, for driving stability of AGV, An accuracy of the sensor should be improved. Therefore, this study proposed sensor signal processing method to improve accuracy of guide sensor, and implemented. The accuracy of sensor in experimentation showed 2.84[mm]. In designing the sensor for controlling AGV posture, the proposed method will be effective.