• The Journal of Korean Physical Therapy
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• 제24권4호
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• pp.268-275
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• 2012

Purpose: This study is to identify how eye movement influences the static balance and fall efficacy of the elderly who have experienced fall-related injuries. Methods: Thirty nine elderly who scored 24 points in the Korean mini mental state examination, were able to walk, and had no specific disease, were selected as the research subjects among elderly who have experienced fall-related injury more than once in the past year. Thus, 20 for the experimental group, and 19 for the control group were selected as subjects. The experiment was conducted for 6 weeks, including periods of evaluation before and after intervention. Results: The results with respect to the dependent variables are as follows: Substitute sample t-testing showed significant differences between each group in eye movement to check difference in balance performance and fall efficacy. When independent sample t-tests were conducted to compare static balancing performance and fall efficacy between the two groups after intervention, they showed significant differences in statistical terms (p<0.05). Conclusion: From the above results of the study, it was found that the application of eye movement combined with diverse fall prevention programs is effective, when enhancing static balance performance power and improving fall efficacy.

• The Journal of Korean Physical Therapy
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• 제26권4호
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• pp.274-279
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• 2014

Purpose: The aim of this study was to determine the change of static and dynamic foot pressure on trunk stabilization exercise in children with spastic diplegic cerebral palsy. Methods: This study examined five male children participants ages 10~14 years old with spastic diplegic cerebral palsy. All subjects participated in a 6-week sling exercise program for trunk stabilization; the exercise was performed three times per week and each session lasted 50 minutes. The subjects were measured for static and dynamic foot pressure and bilateral symmetry of both feet before and after the trunk stabilization exercise. Results: The static foot pressure increased significantly before and after the trunk stabilization exercise (left foot: before $0.41{\pm}0.02%BW/cm^2$ after $0.79{\pm}0.02%BW/cm^2$, right foot: before $0.14{\pm}0.03%BW/cm^2$, after $0.43{\pm}0.44%BW/cm^2$) (p<0.05) and bilateral symmetry of both feet increased (before $0.27{\pm}0.18%BW/cm^2$, after $0.37{\pm}0.05%BW/cm^2$) with more weight shift on left foot than right foot, but was not statistically significant (p>0.05). The dynamic foot pressure increased (left foot: before $2.58{\pm}0.44%BW/cm^2$, after $3.40{\pm}0.31%BW/cm^2$, right foot: before $2.75{\pm}0.19%BW/cm^2$, after $3.26{\pm}0.18%BW/cm^2$) with more weight shift on right foot than left foot, but was not statistically significant (p>0.05), and bilateral symmetry of both feet decreased (before $0.31{\pm}0.36%BW/cm^2$, after $0.13{\pm}0.20%BW/cm^2$) (p<0.05). Conclusion: The findings of this study indicated that the trunk stabilization exercise has a positive impact on static and dynamic foot pressure in children with spastic diplegic cerebral palsy.

• 대한기계학회논문집A
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• 제36권5호
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• pp.497-504
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• 2012

모바일하버는 해상에서 컨테이너 상하역 작업을 하는 새로운 해상물류 시스템이다. 모바일하버용크레인과 같이 해상에서 작업하는 대형 구조물은 파도에 의해 발생하는 지지부의 운동으로 관성력의 영향을 크게 받는다. 따라서 구조물의 안전성에 대한 정확한 검증이 요구되며, 생산 비용을 줄이기 위해 경량화가 매우 중요하다. 이런 요구조건을 위해 동적 응답 최적설계를 수행한다. 등가정하중법은 동하중을 등가정하중으로 변환한 후, 정적 응답 최적화기법을 사용하여 문제를 해결하는 동적 응답 최적설계 방법이다. 지지부의 움직임을 고려한 등가정하중법을 제안하고, 제안한 방법으로 모바일하버용 크레인을 최적화한다.

• 한국산학기술학회논문지
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• 제16권4호
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• pp.2424-2429
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• 2015

유압 피스톤 펌프에서, 고속 상대운동을 하는 실린더 블록과 밸브 플레이트는 누설 및 마찰 손실의 최적화를 위해 극단적으로 제어되어야 하는 특성을 가지고 있으며, 내압 특성 설계는 고압 성능에 매우 중요하지만 이에 대한 응력 해석에 관한 연구가 활발하게 수행되지는 않았다. 따라서 본 논문에서는 CATIA V5를 사용한 정적 응력 해석을 통하여 사판식 유압 피스톤 펌프의 실린더 블록과 밸브 플레이트의 응력과 변위를 해석하고자 하였으며, 실린더 블록의 최대응력은 실린더 뒷부분 동 재질의 접합 소재에 발생하며, 축방향에 비해 반경방향 작용압력이 응력과 변위에 더 큰 영향을 주고, 응력은 약 66%, 변위는 약 30% 더 크게 나타났다. 밸브 플레이트의 경우 재질 및 형상에 대한 검토가 요구됨을 알 수 있었다.

• 한국전문물리치료학회지
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• 제24권1호
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• pp.9-18
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• 2017

Background: Short foot exercise (SFex) is often prescribed and performed in the sport and rehabilitation fields to strengthen intrinsic foot muscles. However, SFex is difficult to perform because of lack of feedback methods. Objects: The aim of this study was to compare the effects of SFex with and without electromyography (EMG) biofeedback on the medial longitudinal arch (MLA) of healthy individuals who maintained a static standing position. Methods: All participants (14 males and 12 females) were randomly divided into two groups (biofeedback and non-biofeedback groups). The EMG activity of the abductor hallucis (AbdH) and tibialis anterior (TA) and the MLA angle on the dominant leg side were measured with the participant in the standing position in the pre- and post-intervention conditions. The intervention session consisted of 15 minutes of SFex with (biofeedback group) or without (non-biofeedback group) EMG biofeedback. The groups were compared using two-way repeated measures analysis of variance. Results: The post-intervention activities of the AbdH muscle (p<.05) and the AbdH/TA ratio (p<.05) were significantly greater in the biofeedback group than in the non-biofeedback group. The activity of the TA (p<.05) and the MLA angle (p<.05) in the biofeedback group were significantly lower in the post-intervention condition than in the pre-intervention condition. Conclusion: The present findings demonstrate that the combination of SFex and EMG biofeedback can effectively facilitate the muscle activity of the AbdH and strengthen the medial longitudinal arch.

• 한국지진공학회논문집
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• 제8권1호
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• pp.39-58
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• 2004

성능에 기초한 내진설계 분야에서 구조물의 내진성능평가를 위해서는 비탄성 지진거동을 보다 정확하게 예즉할 필요가 있다. 성능기초 설계기준에 반영되어 있는 내진성능 평가 방법 가운데 하나인 pushover해석을 이용한 방법은 몇몇 연구자들에 의하여 다양한 해석 방법론이 개발되었다. 이 방법을 사용하여 비탄성 전체 또는 국부적 지진응답을 보다 정확하게 평가하기 위해서는 사용되는 횡하중 분배가 구조시스템과 지반운동의 동적특성에 부합되도록 반영되어야 한다. 그리고 구조물의 변형능력을 합리적으로 평가하여 성능점을 보다 정확하게 산정해야 한다. 본 연구에서는 개선된 적응적 횡하중 분배방법과 건물의 등가응답을 이용하여 비탄성 지진응답을 정확하고 효율적으로 평가할 수 있는 방법을 제안하였다. 제안된 방법은 건물의 전체 비탄성 거동에 대한 내진성능을 평가하고 국부적인 비탄성 지진응답을 정확하게 산정하는데 사용될 수 있다. 또한 제안된 방법의 정확성과 타당성을 검증하기 위해서 비탄성 시간이력해석과 기존의 다른 해석방법들에 의한 비탄성 지진응답과 비교하였다.

• 한국전문물리치료학회지
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• 제18권1호
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• pp.18-27
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• 2011

This study was to investigate the positive effects of specially designed trunk-stabilization exercise program on lower extremity balance of elderly with history of leprosy. In this participants, lower extremity functions has been undermined by the development of damage in peripheral nerves. A total of 40 elderly with history of leprosy were divided into 2 groups of equal size ($n_{1,\;2}=20$): a group that participated in the exercise program, and a control group that did not exercise but did continue to engage in normal daily activities (including walking). The exercise group exercised for 60 minutes 2 days a week for 12 weeks. Static balance ability was measured by asking study participants to a one leg standing test: dynamic balancing ability was measured with a tandem walking test and a timed up-and-go test. The participants in the exercise program and the control group were tested before and after completion of the exercise program for comparison, and then divided according to their ability to feel sensory in the soles of their feet into the categories of normal sensory group: group with sensory loss in one foot: and group with sensory loss in both feet. The participants in the exercise program showed a positive, statistically significant difference in static balance compared with the control group (p<.05) as measured using the one leg standing test. Similarly, the participants in dynamic balance (p<.05) as measured using the tandem walking and timed up-and-go tests. Finally, these improvements were related to the severity of sensory loss in the soles of the feet for all study participants.

• 대한정형도수물리치료학회지
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• 제17권2호
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• pp.11-17
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• 2011

Background: To evaluate the influences of Eye movement program applied to elderly people on static balance. Methods: The subjects consisted of fourteen elderly people. The subjects were divided into two group. The control group (n=7) received no exercise and/or stimulation. The Eye movement program training (E/P) group (n=7) performed balance training using word card and batom. E/P group were accomplished during 4weeks (5 day/week, 60 min/day). All tests were completed before and after experiment. The static balance ability was measured by normal standing when eye open and close on good balance system, respectively. For each case, the experimental data were obtained in 3 item; mean X speed, mean Y speed and velocity moment. Results: The result of this study were as follows: 1. In E/P group, the statistically significants were shown on only mean Y speed in the case of normal standing when eye open (p<.05), but the statistically significants were not shown on mean X, Y speed and velocity moment in the case of normal standing when eye close (p>.05). 2. In control group, the statistically significants were not shown on all posture (p>.05). 3. There was a statistically significant difference on the mean Y speed and velocity moment in the case of normal standing when eye open between control group and E/P group (p<.05). Conclusions: The above results revealed that balance training using Eye movement program were partly effective for improving the static balance ability.

• 대한정형도수물리치료학회지
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• 제15권1호
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• pp.49-57
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• 2009

Purpose : To evaluate the effects hip abductor strengthening exercise using elastic band on static balance. Methods : The subjects consisted of twenty healthy people. The subjects were divided into two group. The control group(n=10) received no exercise and/or stimulation. The elastic band strengthening exercise(E/E) group(n=10) performed hip abductor for strengthening exercise using elastic band. E/E group were accomplished during 6weeks(3day/week, 30-40min/day). All tests were completed before and after experiment. The static balance ability was measured by normal standing when eye open and close on GOOD BALANCE System, respectively. For each case, the experimental data were obtained in 3 items: mean X speed, mean Y speed and velocity moment. Results : The results of this study were as follows; 1. In E/E group, the statistically significants were shown on Y speed and velocity moment in the case of normal standing when eye open and X speed and velocity moment in the case of normal standing when eye close(p<0.05). 2. In control group, the statistically significants were not shown on all posture(p>0.05). 3. There was a statistically significant difference on the X speed and velocity moment in the case of normal standing when eye close between control group and E/E group(p<0.05). Conclusion : The above results revealed that hip abductor strengthening exercise using elastic band were partly effective for improving the static balance ability.

• 대한조선학회논문집
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• 제35권3호
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• pp.26-37
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• 1998

본 논문에서는 시험선 $\ulcorner$나래$\lrcorner$에 적용된 자세 제어 기술 및 그 실해역 시험 결과를 보이고자 한다. $\ulcorner$나래$\lrcorner$는 하부 몰수체와 그에 부착된 제어판을 이용하여 선체를 일정량 부상시키는 복합 지지선형을 채택하여 건조된 선박으로서, 본 연구원의 자체 설계를 거쳐 건조된 유인 시험선이다. 이러한 선형의 선박은 부상 상태에서 Heave, Pitch Roll의 3자유도에 대해 복원력이 거의 작용하지 않기 때문에 정적 불안정성을 가지며, 그에 따라 자세 제어 시스템이 필수적으로 요구된다. 시험선 $\ulcorner$나래$\lrcorner$에는 제어판 구동을 위한 유압 구동 장치 및 선체 운동의 계측을 위한 각종 계측 장비가 설치되었다. 제어기로는 PID 제어기가 사용되었으며, 실시간 제어를 위해 Pentium급 산업용 PC가 탑재되었다. 약 3개월 여에 걸쳐 부상 시험 및 조종 시험을 포함한 실해역 시험이 수행되었으며, 만족스런 제어 성능이 발휘됨을 확인하였다.