• 제목/요약/키워드: Visual condition

검색결과 975건 처리시간 0.033초

Effects of Step Length Change on Kinetic Characteristics While Stepping Over an Obstacle From a Position of Quiet Stance in Young and Elderly Adults: A Preliminary Study

  • Kim, Hyeong-Dong
    • 한국전문물리치료학회지
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    • 제14권4호
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    • pp.66-74
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    • 2007
  • The aim of the present study was to investigate age-related differences in stepping behavior in response to sensory perturbations of postural balance. The participants for this study were 2 healthy elderly adults (mean age=76.0) and 2 younger adults (mean age=25.5). Subjects were asked to step over a 10 cm high obstacle at self-paced speed with the right limb to land on the primary target (normal step length) that is 10 cm in diameter. However, if, during movement, the light was illuminated, then the subject had to step on the secondary target (long step length). It was planned that the onset of the light would be prior to peak Fx of swing limb, between swing peak Fx and swing toe-off, and after swing toe-off. In the younger adults these secondary visual cues were provided at mean times of 240 ms (standard deviation (SD)=11), 402 ms (SD=13), and 476 ms (SD=88) following the movement onset. Corresponding mean times for the healthy elderly were 150 ms (SD=67), 352 ms (SD=39), and 562 ms (SD=115). Results showed great changes in both group and visual cue condition in Fx ground reaction forces and temporal events following the swing toe-off. Swing limb acceleration force (Fx) and stance peak Fx1 was much greater in the young adults compared to the older adults. Both young and older adults increased stance peak Fx2 in the visual cue condition compared to normal stepping. There was no difference in stance peak Fx2 between the visual cue conditions in both groups. Similarly, the time to stance peak Fx2 was much longer for the visual cue condition than for the normal stepping. It was not different between the visual cue conditions in the young adults, but in the elderly mid and late cue was much greater than early cue. In addition, time to stance peak Fx2 and swing and stance time were much longer in the older adults compared to the young adults for the visual cue conditions. These results suggest that unlike young adults, elderly adults did not flexibly modify their responses to unexpected changes in step length while stepping over obstacles.

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몰톤발이 정적 균형 능력에 미치는 영향 (The Effect of Morton's Foot on Static Balance Ability)

  • 한진태;고민지;김영주;최연성;유현남
    • 대한물리의학회지
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    • 제10권2호
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    • pp.81-87
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    • 2015
  • PURPOSE: According to advanced research, the effect of foot type on balance is 3 type. There are squared foot, morton's foot and Egyptian foot. Above all, Morton's foot accounts for 22% of people. The purpose of this study is to find the effect of Morton's Foot on Balance Ability. METHODS: Twenty healthy woman participate in this study(Mean age:23.93; Mean height: 163.35; Mean weight: 56.20). They doesn't have musculoskeletal or neurogical disorder. Ten of participants have morton's foot group, and another ten person are normal foot group. Measurment of balance was used by Balance trainer(BT4) and balance pad(AIREX). Data analyzed in 3 way ANOVA. RESULTS: In foot type and support type of variables, Morton's foot was significant differences in C90 area and Velocity. There was no significant difference between foot type and visual condition. In support type and visual condition of variables, unstable support significantly decreased in Tracelength, C90area and Velocity. If we find out correlationship of foot type, visual condition and support condition, There didn't have relationship each other. CONCLUSION: This study found that correlationship of foot type, visual condition and support condition. But, there are no significant differences. Nevertheless, These results will also be able to offer baseline data about Morton's foot study in future.

천공상태에 따른 수직형 광파이프 시스템의 채광성능 평가 (Daylighting Performance of Lightpipe under Different Sky Conditions)

  • 공효주;김정태
    • KIEAE Journal
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    • 제8권3호
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    • pp.101-106
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    • 2008
  • The use of daylighting has been increased recently due to energy and visual comfort. The aims of interior daylighting are to adequately illuminate visual tasks, to create an attractive visual environment, and to save electrical energy. Lightpipe can improve the distribution of light to interior spaces. This study aims to evaluate the comparative daylighting performance of lightpipe under different sky conditions with mock-up model, sized $6m{\times}6m{\times}4m$ ($w{\times}d{\times}h$). For the purpose, perpendicular lightpipe system was designed as 650 diameter, with an aspect ratio of 2. Totally 49 measuring points of and two of outdoor illuminance on the horizontal plane were monitored from 09:00 to 18:30 on April 29 and May 15 2008. Agilent data logger and photometric sensor were used. Light factor were used to analyse daylight performance under different sky condition. Under overcast sky condition and clear sky condition, the lightpipe system is suitable for KS recommendation level of illuminance.

시각과 고유수용성 감각이 요부 운동의 정확도에 미치는 영향 (The Effect of Vision and Proprioception on Lumbar Movement Accuracy)

  • 심현보;윤홍일;윤이나
    • 대한정형도수물리치료학회지
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    • 제13권2호
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    • pp.31-44
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    • 2007
  • The purposes of this study were to examine the normal lumbar proprioception and identify the effect of vision and proprioception on lumbar movement accuracy through measuring a reposition error in visual and non-visual conditions and to provide the basic data for use of vision when rehabilitation program is applied. The subjects of this study were 39 healthy university students who have average physical activity level. They were measured the ability to reproduce the target position(50% of maximal range of motion) of flexion, extension, dominant and non-dominant side flexion in visual and non-visual conditions. Movement accuracy was assessed by reposition error(differences between intended and actual positions) that is calculated by the average of absolute value of 3 repeated measures at each directions. The data were analysed by paired samples t-test, independent samples t-test, and repeated measures ANOVA. The results were as follows : 1. Movement accuracy of flexion, extension, dominant side flexion, and non-dominant side flexion was increased in visual condition. 2. There were no differences in the lumbar movement accuracy between sexes in visual and non-visual conditions. 3. In non-visual condition, the movement in coronal plane(dominant and non dominant side flexion) is more accurate than that in sagittal plane(flexion and extension). 4. In non-visual condition, there were no differences in the lumbar movement accuracy between dominant and non-dominant side flexion. In conclusion, this study demonstrates that the movement is more accurate when the visual information input is available than proprioception is only available. When proprioception is decreased by injury or disease, it disturbs the control of posture and movement. In this case, human controls the posture and movement by using visual compensation. However it is impossible to prevent an injury or trauma because most of injuries occur in an unexpected situation. For this reason, it is important to improve the proprioception. Therefore, proprioceptive training or exercise which improve the ability to control of posture and movement is performed an appropriate control of permission or interception of the visual information input to prevent an excessive visual compensation.

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자연형 IVB(Independent Visual Background)의 Simulator Sickness 감소효과 (Effects of Natural Independent Visual Background for Reducing Simulator Sickness)

  • 김도회;임정위
    • 산업경영시스템학회지
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    • 제25권3호
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    • pp.28-33
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    • 2002
  • Several studies indicated that an independent visual background (IVB) reduced simulator sickness (SS) and balance disturbance associated with exposure to virtual environments (VEs) and motion simulators. A recent study showed that an IVB comprised of an earth-fixed grid was less effective in a complex driving simulator than in a simple VE. Subjects' post-experiment reports indicated that the VE motion "induced" motion of the earth-fixed grid m. This led to the suggestion that an IVB comprised of clouds would be less subject to induced motion and therefore would alleviate nausea more effectively than a grid IVB. Clouds are "natural" and are usually perceived as relatively stable, whereas a grid has no inherent stability. 12 subjects were exposed to complex motion through a simulated environment in a driving simulator under 3 IVB conditions: grid, less clouds, many clouds. They reported less nausea when the many-cloud IVB was used relative to the grid IVB condition. grid IVB condition.

색각 시표에 따른 시피질 뇌파의 반응 상태 (Response State of EEG Wave Type on Visual Cortex According to Color Vision Target)

  • 김덕훈
    • 한국안광학회지
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    • 제5권2호
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    • pp.5-9
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    • 2000
  • 시유발전위는 시피질 뇌파의 반응을 알 수 있는 전기 생리학적인 검사법이다. 이 검사는 눈의 기능을 타각적으로 검사하는 검사법이다. 본 연구는 색각에 대한 객관적인 검사를 위해 시유발전위를 사용하였다. 검사조건은 거리와 조명의 차이를 다르게 한 상태에서 실시하였다. 피검자는 한국인 성인으로 정상색각자를 대상으로 하였다. 수렴운동 상태에서 색각의 시표적에 따라서 시자극에 관계하는 시피질의 뇌파의 빈도는 델타파가 가장 많고, 다음으로 메타파, 세타파 그리고 알파파의 순으로 나타났다. 뇌파의 진폭에 대한 히스토그램은 거의 비정규분 포곡선을 가지며, 위상 분석에서는 대게 선형을 나타내었다. 시표의 종류에 따른 뇌파의 빈도는 비슷한 결과를 나타내었다.

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시각 흐름 속도에 따른 가상현실 프로그램이 뇌졸중 환자의 보행에 미치는 영향 (The Effects of Visual Flow Speed's Modulation-Based Virtual Reality Program on Gait Function in Stroke Patients)

  • 강형규;정이정
    • 한국산학기술학회논문지
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    • 제13권1호
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    • pp.247-253
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    • 2012
  • 본 연구는 시각흐름 속도에 따른 가상현실 프로그램이 뇌졸중 환자의 보행에 미치는 영향을 알아보고자 시행하였다. 연구 대상자는 서울시 소재 M재활전문병원에 입원 중인 뇌졸중 환자 중 무작위로 31명을 선정하였고 대상자는 가상현실 프로그램에 몰입하여 보행분석기 위에서 보행을 실시하였으며 가상현실 프로그램의 4가지 조건은 정상 보행과 0.25배, 1배, 2배의 시각흐름 속도변환 가상현실 프로그램으로 구성되었다. 중재동안 보행분석은 GaitRite보행분석시스템을 이용하여 보행 속도, 분속수, 활보장, 보장, 단하지지지 시간, 양하지지지 시간을 측정하였다. 그 결과 0.25배의 느린 시각흐름 가상현실 프로그램에서 연구 대상자는 보행속도, 분속수, 환측 활보장, 건측 활보장, 환측 보장, 건측 활보장이 통계적으로 유의하게 감소하였고(p<.05), 환측 단하지지지시간, 건측 단하지지지시간, 환측 양하 지지지시간, 건측 양하지지지시간이 통계적으로 유의하게 증가하였다(p<.05). 또한 2배의 빠른 시각흐름 가상현실 프로그램에서 연구 대상자는 보행속도, 분속수, 환측 활보장, 건측 활보장, 환측 보장, 건측 활보장, 환측 단하지지지시간이 유의하게 증가하였고(p<.05), 건측 단하지지지시간, 환측 양하지지지시간, 건측 양하지지지시간이 유의하게 감소하였다(p<.05). 따라서 가상현실 보행 프로그램의 적용 속도에 따라서 뇌졸중 환자의 보행 능력이 유의하게 차이를 나타낸다는 것을 알았다. 그러므로 뇌졸중 환자의 운동 프로그램을 계획할 때 보행 훈련 프로그램을 증가시킬 수 있는 다양한 훈련 프로그램이 요구된다.

외발서기 시 시각정보 차단에 따른 인체 균형 특성 변화 분석 (Changes in Balance Characteristics Affected by the Visual Information during Single Leg Stance)

  • 박정홍;김광훈;염창홍;손권
    • 한국정밀공학회지
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    • 제28권11호
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    • pp.1323-1329
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    • 2011
  • The purpose of study was to analyze how the visual information affects balance control of individuals during single leg stance. A total of 27 young normal people (20 males and 7 females, age: $13.7{\pm}2.6$, height: $162.3{\pm}13.2$ cm, weight: $53.9{\pm}13.9$ kg) was voluntarily involved in the experiment. The subjects were requested to maintain balance for 20 seconds with eyes both open and closed on a force plate and then foot ground reaction data were collected for that duration. Results showed that mean velocity of COP in closed eyes condition was larger 1.84 times than that of the open-eyes condition and range of vertical angle was increased approximately one degree in the closed eyes condition. To accomplish a balance, the frequency power in mediolateral and anteroposterior components of the foot-ground reaction force was increased by 1.3~1.4 times. Consequently, visual absence during single leg stance can result in critical loss of balance and lead to instability of body control.

대학생의 정기적 시력검진 실태에 관한 연구 (Actual Condition of Periodic Visual Acuity Testing for Undergraduate Students)

  • 이옥진
    • 한국안광학회지
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    • 제12권3호
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    • pp.117-120
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    • 2007
  • 대학생 304명을 대상으로 정기적 시력검진의 실태를 조사, 분석하여 안보건교육 프로그램의 개발 및 교육의 실시를 위한 자료를 얻고자 하였다. 연구대상의 59.21%가 정기적 시력검진을 받지 않는 것으로 나타났으며 여학생의 정기적 시력검진률이 남학생보다 높게 나타났다. 도시출신의 정기적 시력검진률이 43.07%, 농 어촌출신이 24.32%로 유의한 차이를 보여주었으며(p<0.05) 4년제 대학생의 정기적 시력검진률이 65.71%, 2-3년제 대학생이 27.64%로 유의한 차이를 보여주었다(p<0.001). 시력을 교정한 대학생의 정기적 시력검진률이 50.25%, 시력을 교정하지 않는 대학생이 23.36%로 유의한 차이를 보여주었다(p<0.001).

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Muscle Activity Based on Real-time Visual Feedback Training Methods by Rehabilitative Ultrasound Image in Elderly and Relationship between Heckmatt Scale, Muscle Thickness and Tone : A Pilot Study

  • Shin, Janghoon;Lee, Wanhee
    • Physical Therapy Rehabilitation Science
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    • 제10권1호
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    • pp.82-89
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    • 2021
  • Purpose: This study is to investigate the muscle activity based on real-time visual feedback training methods by rehabilitative ultrasound image in elderly and correlation between Heckmatt scale grade, muscle tone and thickness. Design: Cross-sectional study: Pilot study Methods: 6 elderly participated in the study with 2 conditions. Under the condition of rehabilitation ultrasound imaging equipment, all subjects performed voluntary maximal muscle contraction of the quadriceps 3 times using visual feedback based on Rehabilitative Ultrasound Imaging 1.0 (RUSI 1.0). Under the condition of only ultrasound images, all subjects performed voluntary maximal muscle contraction of the quadriceps 3 times using ultrasound image-based visual feedback. The muscle thickness and tone of the quadriceps were measured and the grades were classified by Heckmatt scale and all variables were comparative analyzed. Results: Heckmatt scale grade showed a negative correlation with muscle thickness at relaxation (p<0.05), and a negative correlation with the difference value obtained by subtracting muscle thickness at relaxation from muscle thickness at contraction in ultrasound image condition (p<0.05). The muscle tone during relaxation showed a negative correlation with the muscle thickness during relaxation (p<0.05). Conclusion: In the case of voluntary maximum muscle contraction of the quadriceps muscle in the elderly, it can be seen that the muscle thickness is getting larger when the RUSI 1.0-based visual feedback is provided than with only ultrasound image provided. And the lower Heckmatt scale grade is, the thicker the muscle is, and the lower the muscle tone is.