• The Journal of Korean Physical Therapy
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• 제26권4호
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• pp.257-261
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• 2014

Purpose: The purpose of this study was to compare plantar foot pressure distribution in adults and elderly according to obstacle height. Methods: Nine healthy adults and nine older adults were recruited and the subjects provided written informed consent consent prior to participation. Both groups walked and crossed obstacles with heights of 0%, 10%, 20%, and 30% of their height. Foot pressure was measured by peak pressure using the Pedar System (Novel Gmbh, Germany) during obstacle walking with barefeet in shoes. Three trails were calculated on eight areas and then averaged for data analysis. Results: A significant difference in great toe, little toes, and lateral metatarsal area was observed between adults and elderly groups, but other areas did not show significant differences. Foot pressure was increased in groups according to obstacle height. Conclusion: These findings showed that change in foot pressure distribution is more lateral in elderly in order to maintain postural control during obstacle crossing.

• The Journal of Korean Physical Therapy
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• 제21권3호
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• pp.75-80
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• 2009

Purpose: The purpose of this study was to examine the effect of an obstacle height on the balance control of older adults while stepping over an obstacle from a position of quiet stance. Methods: Fifteen community-dwelling healthy older adults (mean age, $74.4\pm4.27$ yrs; age range, 67-82 yrs) volunteered to participate in this study. The subjects performed gait initiation (GI) and they stepped over obstacles of two different heights (10 cm and 18 cm) at a self-paced speed from a position of quiet stance. Their performance was assessed by recording the changes in the displacement of the COP in the anteroposterior (A-P) and mediolateral (M-L) directions using a force platform. Results: The M-L displacement of the COP significantly increased for an 18 cm obstacle height condition as compared to the GI and a 10 cm obstacle height condition (p<0.01). Furthermore, the M-L displacement of the COP for a 10 cm high obstacle was significantly greater for that for the GI (p<0.01). However, the mean of the A-P displacement of the COP was similar between the stepping conditions for the A-P displacement of the COP (p>0.05). Conclusion: This study suggests that the M-L COP displacement could be a better parameter to identify the dynamic balance control in older adults when negotiating obstacles.

• The Journal of Korean Physical Therapy
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• 제23권2호
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• pp.1-5
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• 2011

Purpose: This study examined the difference in the center of pressure (COP) displacement time in older adults according to the obstacle height during stance at each sub.phase when crossing obstacles. Methods: Fifteen older adults were enrolled in this study (${\geq}65$ years of age). The F-scan was used to measure the COP displacement time when crossing a 0, 10 and 40cm obstacle, and the stance phase was divided into 4 sub-phases according to the foot contact pattern. Results: During the stance phase, the COP displacement time increased with increasing obstacle height. During the mid-stance, terminal stance and pre-swing except for the loading response, there were significant differences in the COP displacement time according to the obstacle height. Conclusion: This study suggests that older adults show differences in the COP displacement time according to the stance sub-phase while crossing obstacles, and they use different mechanisms according the sub-phases to maintain balance during obstacle crossing.

• 대한물리치료과학회지
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• 제15권3호
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• pp.55-63
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• 2008

Background : The Purposes of this study were to understand difference between free walking and obstacle over walking through the naked eye and motion analysis device, and to review merits of obstacle walking training as item of functional assessment in clinical situations. Methods : All participants were male and performed 3 types of walking methods: free walking, obstacle over walking with low block(height=10cm, width=8cm), and obstacle over walking with high block(height=20cm, width=8cm). All walking were performed 3 trials respectively. Results : In the naked eye, initial contact with toes occurred more than heel strike in obstacle over walking, and the flexion angle of hip and knee were increased in obstacle over walking. On interpretations though motion analysis device, cadence, gait speed and weight accept were significant statistically(p<.05). Cadence and gait speed were decreased, and weight accept duration was increased in obstacle over walking. Rotation among three pelvic motions was significant statistically(p<.05), flexion among three hip motions was significant statistically(p<.05) and flexion among three ankle motions was significant statistically(p<.05). Rotation and flexion among three ankle motions was significant statistically(p<.05). Conclusion : Both the naked eye and interpretations of the device presented many difference between free walking and obstacle over walking. In overcrossing obstacles, many participants appeared walking strategy by perform initial contact with toes. Knee flexion was most significant statistically(p<.05) in obstacle over walking with 20cm block.

• 한국운동역학회지
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• 제18권2호
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• pp.11-17
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• 2008

파킨슨 환자들이 장애물에 걸려서 넘어지는 것은 위험한데, 아직까지 이와 관련된 연구는 미비한 실정이다. 본 연구의 목적은 장애물 보행을 성공적으로 수행한 5명을 대상으로, 4가지 높이(0, 2.5, 5.2, 15.2cm)의 장애물을 넘을 때 나타나는 보행 특성의 차이를 밝히는 것이다. 연구결과, 파킨슨 환자들은 장애물 높이가 높아질수록 장애물에 더 천천히 접근하였으며, 장애물의 높이가 높을수록 발이 장애물에 걸리지 않도록 더 높이 발을 들어 넘었다. 또한, 파킨슨 환자들은 장애물의 높이가 높을수록 더 안정되게 넘기 위해서 좌.우발 사이의 거리를 넓게 해서 넘었다. 파킨슨 환자들은 각 장애물별로 넘는 속도를 일정하게 하고, 장애물을 넘기 전 왼발 앞꿈치와 장애물과의 수평거리 및 장애물과 장애물을 넘은 오른발 뒷꿈치와의 수평거리에서 차이가 없이 장애물을 넘었다. 이와 같은 특성이 파킨슨 환자들이 장애물을 넘는 일반적인 전략인 것으로 판단된다. 결론적으로 파킨슨 환자들은 장애물을 천천히, 조심스럽게, 그리고 비효율적으로 넘는 것으로 나타났다.

• 한국운동역학회지
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• 제17권4호
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• pp.141-148
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• 2007

Falls associated with tripping over an obstacle can be dangerous, yet little is known about the strategies used for stepping over obstacles in older Parkinson disease. The purpose of this study was to investigate the lower extremity muscle activity on the obstacle gait according to obstacle height in older Parkinson diseases. The obstacle gait of 7 older Parkinson disease was examined during a 5.0 m approach to, and while stepping over, obstacles of 0, 25, 52, and 152mm. Seven pairs of surface electrodes(Noraxon MyoResearch, USA) were attached to the right-hand side of the body to monitor the adductor longus(AL), gluteus medius(GME), gluteus maximus(GMA), biceps femoris(BF), rectus femoris(RF), gastrocnemius(GA), tibialis anterior(TA). Electromyography data were filtered using a 10Hz to 350 Hz Butterworth band-pass digital filter and normalized to the maximum value in the analyzed phases. A one-way ANOVA for repeated measures was employed for selected electromyography variables to analyze the differences of the height of four obstacles. The results showed significant differences between 0.0mm and 25, 52, and 152mm obstacle height in TA and GA activities during the second phase(swing phase). But the more increase obstacle height, the more not increase the muscle activities. This means that the Parkinson disease stepping over obstacle inefficiency. To prevent and reduce the frequency of falls, elderly Parkinson disease maintained and improved their balance, muscular strength, neuromuscular control and mobility.

• 한국운동역학회지
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• 제20권2호
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• pp.129-137
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• 2010

The purpose of this study is to investigate the effect of a 12-week aquatic exercise on obstacle gait in older women. Originally, 20 healthy female elderly participated this study but 12 of them completed the program. All participants were trained in the aquatic exercise program by an authorized trainer. They had come to the authors' lab three times during training period(0, 6, 12 weeks) and performed obstacle gait with three different height(0, 30, and 50% of leg length). After performed 3-Dimensional motion analysis following results were found. (1) For the CV, MVHC, TC, HC, statistically significances were shown in obstacle height. Although significant training effects were not shown, all variables showed typical patterns and it was considered as efficient motion to overcome the height obstacles. (2) The anterior-posterior and vertical GRF of support leg during support phase were revealed in height effect but in training one. However, differences between Peak 1 and Peak 2 in vertical GRF increased as training period increased. (3) Knee and hip resultant joint moments were affected by training but ankle resultant moments remained unchanged.

• 한국해안·해양공학회논문집
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• 제34권6호
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• pp.211-221
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• 2022

파의 처오름높이는 제방, 호안 및 방파제와 같은 해안 구조물의 설계에 영향을 미치는 가장 중요한 매개변수 중 하나이다. 본 연구에서는 비정수압 수치모형인 SWASH(Zijlema et al., 2011)를 이용해 고정된 수중 및 부유식 사각형 구조물에 의한 고립파의 처오름높이 저감 효과를 분석하였다. SWASH 수치모형이 고립파의 전파, 쇄파 및 처오름현상을 매우 잘 재현하는 것을 확인하였다. 또한 수중 및 부유식 사각형 구조물에 의한 고립파의 파랑변형을 잘 재현하는 것을 확인하였다. 마지막으로 수중 및 부유식 사각형 구조물의 처오름높이 저감 효과를 검토하였다. 부유식 구조물의 에너지 감쇠효과는 수중 구조물보다 크고, 처오름높이 저감에 더 효과적인 것으로 나타났다.

• 대한기계학회논문집
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• 제17권7호
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• pp.1864-1873
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• 1993

A biomechanical approach was carried out to analyze foot-floor reaction forces acting on five male subjects performing a walking task. The task analyzed was walking over an obstacle with the right bare foot. The foot-floor reaction data were measured from a force plate, and then processed using a software developed. The source program was coded in the C language for easier on-line data acquisition and graphic displays. High repeatability was found in the reaction data acquired from three trials by each subject. For obstacle height from 0 to 25 cm, the maximum in reaction force reached up to 1.048 BW in the vertical, 0.174 BW in the anterior-posterior, and 0.054 BW in the medio-lateral components, respectively. A quantity was defined by the difference between two vertical reaction values, and this quantity was found to be proportional to the obstacle height. It was also shown that the whole body motion could be predicted the measured foot-floor reaction data.

• 한국정밀공학회지
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• 제30권4호
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• pp.383-389
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• 2013

Demand for high-rising building has arisen. However, its maintenance is usually executed by labour. It could have a severe problem. We proposed a gondola robot to solve it. In this paper, we designed a height estimation sensor for this gondola. It is consist of pan-tilt unit, ARS sensor, and laser sensor. The pan-tilt unit keeps the laser sensor to indicate the gravity direction by referencing the ARS. The laser sensor's range is vertical distance from gondola to ground. However, if there is an obstacle under the gondola, the distance includes its height. To filter it out, we apply a Kalman filter for the height estimation. If the estimated height is changed extremely, the filter decides that there is an obstacle. Then, it remembers the height of obstacle. Other extreme changes of height estimations are reflected. The experimental results using the proposed sensor system show detail flow of the height estimation.