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

• 한국전문물리치료학회지
• /
• 제15권3호
• /
• pp.35-43
• /
• 2008

The purpose of this study was to compare spatio-temporal parameters during walking between patients with idiopathic Parkinson's disease and a control group matched for age, height, and weight. Thirty-three subjects were included in this study. Fifteen normal subjects (age, $63.3{\pm}5.8$ yrs; height, $164.1{\pm}8.7$ cm; weight, $60.7{\pm}17.5$ kg) and eighteen patients (age, $64.0{\pm}7.7$ yrs; height, $164.7{\pm}7.3$ cm; weight, $63.6{\pm}7.7$ kg) participated in the study. The Vicon 512 Motion analysis system was used for gait analysis in each group during walking, with and without an obstacle. The measured spatio-temporal parameters were cadence, walking speed, stride time, step time, single limb support time, double limb support time, stride length, and step length. Results in stride length and step length, when walking without an obstacle, showed a significantly greater decrease in the patient group compared to the control group. During walking with an obstacle, the patient group showed a significantly greater decrease in the step length as compared to the control group. For the control group, there were significant decreases in parameters of cadence and walking speed and increases in parameters of stride time, step time, and single limb support time when walking with an obstacle. The patient group had lower cadence and walking speed and higher stride time, step time, and single limb support time during walking with an obstacle than in walking without an obstacle. These results suggest that patients with Parkinson's disease who walk over an obstacle can decrease cadence, stride length, and step length. Further study is needed, performed with more obstacles and combined with other external cues, such as visual or acoustic guides.

• 한국전문물리치료학회지
• /
• 제18권3호
• /
• pp.16-25
• /
• 2011

This study aimed to evaluate factors related to the ability of ambulatory patients with cerebral palsy (CP) to walk over vertical and horizontal obstacles. Twenty patients with spastic CP who were able to walk independently for at least 10 m with or without walking devices were recruited for the study. Participants were required to walk over small obstacles (1, 4, and 8 cm in height or width; total of 6 conditions). A 'fail' was recorded when either the lower limbs or the walking device contacted the obstacle. Linear regression analyses were used to determine the effects of age, sex, walking devices, eyeglasses, subtype (hemiplegia or diplegia), ankle foot orthoses, functional level, and score of body mass index on the ability of obstacle crossing. Fifteen participants (75%) failed to adequately clear the foot or walking device over obstacles in at least 1 condition. The chance of failure in crossing vertical obstacle was affected by the use of ankle foot orthoses, eyeglasses, gender, and CP subtype (p<.05). The failure rate crossing horizontal obstacle was affected by CP subtype. These findings suggest that rehabilitation procedures should (1) consider the clinical characteristics of patients in order to prepare them to be more independent while performing daily activities, and (2) incorporate environmental conditions that patients encounter at home and in the community.

• 대한물리의학회지
• /
• 제17권3호
• /
• pp.51-58
• /
• 2022

PURPOSE: This study aimed to evaluate the correlation between executive function and gait evaluations for the elderly, and validate the obstacle gait evaluation as a cognitive impairment test tool. METHODS: This study was a cross-sectional design. 79 people aged 65 years or older were selected as subjects. The Korean version of the Mini-Mental State Examination (MMSE-KC) to evaluate overall cognitive function and the Trail Making Test (TMT) A, B to measure executive function were performed. The 4-meter walking speed test and the walking speed test while crossing over an obstacle were carried out to evaluate gait. The Spearman's correlation was used to measure the correlation between cognition and gait speed. RESULTS: There was no significant correlation between the 4 m gait speed and executive function( TMT-A (p = .056), TMT-B (p = .115)). However, there was a significant correlation between the 4 m gait speed and MMSE-KC (r = .277, p < .05). There was also a significant correlation between walking speed while crossing over an obstacle and all tests (MMSE-KC (r = .382, p < .01). TMT-A (r = -.327, p < .01), TMT-B (r = -.283, p < .05)). CONCLUSION: It was found that the gait speed while crossing over an obstacle was correlated with all cognitive function tests. Therefore, we suggest the use of the gait speed test while crossing over an obstacle rather than the simple gait test to diagnose cognitive decline.

• 대한기계학회논문집A
• /
• 제37권2호
• /
• pp.169-176
• /
• 2013

알려지지 않은 실내에서 인간형 로봇의 이동경로 생성을 위해서는 주변 장애물의 형태를 정확히 인식하여 이에 적합한 로봇 움직임을 만들어야 한다. 이 때, 인식된 장애물의 형태에 따라 로봇이 접촉없이 통과할 수 있고, 발과 접촉하여 통과할 수도 있으며, 회피할 수도 있다. 이를 위해 장애물이 어떤 형태를 갖고 있는지를 분류하여 로봇의 이동경로를 생성할 때 활용 가능한 장애물 인식 및 분류 방법을 제안한다. 특히 장애물 형태를 정확히 인식하기 위한 기존 알고리즘은 많은 계산량으로 실시간 활용에 어려움이 있으며, 불필요한 장애물도 함께 추출하기 때문에 연산자원의 낭비가 불가피하다. 본 연구에서는 장애물 인식의 계산량을 줄이기 위해 장애물의 영역을 분류한 후 정확한 형상이 필요한 장애물에 한해 크기 및 형태를 추출하도록 알고리즘의 적용 범위를 제한하여 계산량을 줄이는 방법을 제안한다.

• 한국전문물리치료학회지
• /
• 제22권4호
• /
• pp.71-78
• /
• 2015

Previous studies have investigated stepping over obstacles in treadmill walking training (TWT-OS) and treadmill walking training (TWT) alone for walking capacity not considering real physical activity. As such, we investigated the effects of TWT-OS on physical activity and changes in different levels of physical activity based on community ambulation in stroke patients. Thirty subjects were randomly assigned to either the experimental group or the control group, with 15 and 15 subjects, respectively. However, one subject from the control group was excluded because of inadequate treatment sessions. All subjects underwent routine physical therapy in the form of treadmill walking. The subjects in the experimental group underwent simultaneous training in obstacle-stepping while walking on the treadmill for 30 min/day, five times/week, for four weeks. Subjects were given a three-axis accelerometer to wear at the hip on a belt for one-week pre- and post-training physical activity. Step counts for seven days, average daily step counts, and the average of minutes spent in sedentary, light, and above moderate activity were chosen as outcome measures of physical activity. No significant differences between the groups were found in terms of step counts for seven days, average daily activity, or daily activity spent at sedentary levels after four-week interventions. However, the average daily activity spent at light levels (-42.60 min vs. -6.71 min) was significantly lower in the experimental group than in the controls. Conversely, average daily activity spent at above moderate levels was higher (19.86 min vs. 11.07 min) (p<.05) after adjusting for each baseline value. Significant pre- and post-training differences were found in all variables of the experimental group (p<.05). Thus, TWT-OS could improve physical levels above moderate activity as a community-oriented task more than simple repetitive waking on a treadmill, and it could provide an opportunity for patients ambulatory after stroke to participate in the community again.

• EDISON SW 활용 경진대회 논문집
• /
• 제5회(2016년)
• /
• pp.489-492
• /
• 2016

In this paper, 본 논문에서는 경사/장애물/특수표면을 이동할 수 있는 얀센 매커니즘 기반의 보행기구 설계에 대해 다루고 있다. 얀센 매커니즘 자체의 조건과 전체 보행기구의 조건을 알아보며, 기구의 완전한 회전운동 조건과 장애물이 있는 거친 표면을 이동할 수 있는 조건을 알아보고자 한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.645-650
• /
• 2003

Legged robots can avoid an obstacle by crawling-over or striding, according to the obstacle’s nature and the current state of the robot. Thus, it can be observed that the mobility efficiency to reach a destination is improved by such action. Moreover, if robots have many legs like 4-legged or 6-legged types, then the robot movement range is affected by the order of swing leg. In this paper, the avoidance action of a quadruped robot is generated by a neural network (NN) whose inputs are information on the position of the destination, the obstacle configuration and the robot's self-state. To realize a free gait in static walking, the order of swing leg is determined using an another NN whose inputs are the amount of movements and the robot’s self-state. The design parameter of the latter NN is adjusted by using genetic algorithm (GA).

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 하계종합학술대회논문집
• /
• pp.565-568
• /
• 1998

In this paper, we implemented the electornic moving aid system for safe walking of the blind. An obstacle detecting of each sector used ultrasound and a distance measurement used time of flight. The alarm is designed to have a sound and a tactile function that can be selected on an user's convenience. This system can detect and obstacle of upward, forward, downward and optimally warn to the blind with vibration, beep sound by appling warning algorithm on object detection. Experimental testing and performance evaluation have been successfully carried out with a prototype cane, and the experiment shows the capability of the function to detect unknown objects within an assigned distance, under knees, over head height, and crushed puddles.

• 한국운동역학회지
• /
• 제18권2호
• /
• pp.1-9
• /
• 2008

본 연구는 장애물을 넘는 동안 장애물의 높이 변화가 보행 시 족저압에 미치는 영향을 알아보기 위해 실시하였으며 이를 위해 족저 최고 족저압과 최대 힘, 압력 중심의 이동 경로를 중심으로 자료를 수집하여 분석하였다. 근골격계에 문제가 없는 열여섯 명의 건강한 젊은 성인이 이 연구에 참여하여 맨발로 각각 평지, 10cm, 20cm 그리고 30cm의 장애물을 넘는 동안 입각기 발의 족저 최고 족저압과 최대 힘, 압력중심 이동경로를 측정하였다. 측정은 Tekscan사의 Footmat system을 이용하였으며, 대상자의 발을 일곱 개의 영역(두 개의 발가락 영역, 세 개의 전족부 영역, 한 개의 중족부와 후족부 영역)으로 나누어 수집한 자료를 일원배치분산분석을 이용하여 분석하였다. 본 연구를 통해 높이가 다른 여러 가지 장애물을 넘을 때, 입각기 동안 족저의 영역별 최고 족저압과 최대 힘은 발가락부위에서 유의하게 증가하는 것을 알 수 있었고 후족부위에서는 감소하였다. 그리고 장애물의 높이가 높아질수록 압력중심 이동경로가 짧아지면서 전족부에서 외전하는 경향을 볼 수 있었다. 따라서 본 연구에서는 장애물 보행 시 장애물의 높이가 발의 구조와 기능에 영향을 미친다는 것을 확인할 수 있었다.