• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.11-17
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• 2008

Falls associated with tripping over an obstacle can be dangerous, yet little is known about the strategies used for stepping over obstacles by Parkinson's patients. The purpose of this study was to investigate stepping over gait characteristics according to obstacle height in Parkinson's patients. The gait of 7 Parkinson's patients was examined during a 5.0 m approach to, and while stepping over, obstacles of 0, 2.5, 5.2, and 15.2 cm. Only five Parkinson's patients were able to clear all obstacles successfully; as such, only their data were analyzed. A one-way ANOVA for repeated measures was employed for selected kinematic variables to analyze the differences of the height of four obstacles. The results showed significant differences between obstacle height and: approaching speed (AS), foot clearance from the obstacle(FC), and step width (SW). The results showed no significant differences between obstacle height and: crossing speed (CS), toe distance (TD), and heel distance (HD). This strategy tends to reduce the risk of toe contact with the obstacle. Parkinson's patients were stepping over the obstacle slowly, stably and inefficiently.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.1
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• pp.69-74
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• 2014

PURPOSE: The aim of this study is to compare the spatio-temporal gait parameters between paretic and non-paretic limb while stepping over the different obstacle's heights in subjects with stroke. METHODS: Nine subjects with stroke were participated in this study. Subjects were asked to step over obstacles with a different height. 8 camera motion analysis system(Motion Analysis Corporation, Santa Rosa, USA) was used to measure spatio-temporal parameters. The two way repeated measurement ANOVA was used to compare spati-temporal gait parameters between paretic and non-paretic limbs while stepping over a different obstacle's height(0cm, 10cm, 20cm). RESULTS: Step width, velocity, single supoort time, and double support time were not different among obstacle's height(p>0.05) but stride length, step length, and cadence were significantly different(p>0.05). In stride length, cadence, and double support time, the interactions between obstacle's heights and limbs were not different(p>0.05) but it was significantly different in velocity, step length, and single support time(p<0.05). Velocity, stride length, cadence, and double support times were not different between paretic limb and non-paretic limb(p>0.05) but step length and single support times were significantly different between paretic limb and non-paretic limb(p<0.05). CONCLUSION: These results show that there are differences with spatio-temporal gait parameters among obstacle's heights and between paretic and non-paretic limb during obstacle crossing in subjects with stroke.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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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.

• The Journal of Korean Physical Therapy
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• v.21 no.3
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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 Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.9
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• pp.547-555
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• 2005

A fault-tolerant gait of multi-legged robots with static walking is a gait which can maintain gait stability and continue its walking against an occurrence of a leg failure. This paper proposes fault-tolerant gait planning of a quadruped robot walking over a rough planar terrain. The considered fault is a locked joint failure, which prevents a joint of a leg from moving and makes it locked in a known position. In this Paper, two-phase discontinuous gaits are presented as a new fault-tolerant gait for quadruped robots suffering from a locked joint failure. By comparing with previously developed one-phase discontinuous gaits, it is shown that the proposed gait has great advantages in gait performance such as the stride length and terrain adaptability. Based on the two-phase discontinuous gait, quasi follow-the-leader(FTL) gaits are constructed which enable a quadruped robot to traverse two-dimensional rough terrain after an occurrence of a locked joint failure. During walking, two front legs undergo the foot adjustment procedure for avoiding stepping on forbidden areas. The Proposed wait planning is verified by using computer graphics simulations.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.418-432
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• 2002

본 연구의 목적은 다음과 같이 네 가지이다. 첫째, dual-strategy hypothesis 모델의 이론적인 배경을 서술한다. 둘째, 보행시작 시 (Gait Initiation)와 장애물 보행시작 (Stepping over obstacles)시의 motor task를 dual-strategy hypothesis 모델의 관정에서 서술한다. 셋째, 파킨슨씨 환자군과 뇌졸증 환자군을 이 모델의 관점에서 서술한다. 마지막으로, dual strategy hypothesis모델의 임상적용 가능성에 대해서 간단히 서술하는 것이다.

• Physical Therapy Korea
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• v.26 no.4
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• pp.35-41
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• 2019

Background: Obstacle training affects lower limb muscle activity, balance, reducing the risk of falls, and making gait more stable. Objects: This study aimed to investigate the effects of aquatic and ground obstacle training on balance and muscle activity in patients with chronic stroke. Methods: The study subjects included 30 patients with stroke, who were divided into aquatic ($n_1=15$) and ground ($n_2=15$) groups. Groups underwent obstacle training three times per week, 30 min per session, for six weeks that went as follows: walking over sites with the paralyzed leg, stepping onto and down from a box step, and walking over obstacles with the non-paralyzed leg. Results: The experimental results were obtained by comparing muscle activity. Activity of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius were significantly increased in the aquatic group (p<.05). Activity of the biceps femoris and tibialis anterior were significantly increased in the ground group (p<.05); however, the rectus femoris and gastrocnemius were not significantly different. In the comparison of maximal distance regarding the limits of stability, it was significantly increased on the non-affected side, affected side, and anterior and posterior distance in the aquatic group (p<.05). It was significantly increased in the non-affected side and anterior and posterior distance the ground group (p<.05); however, maximal distance on the affected side distance was not significantly different. Conclusion: Gait training with aquatic and ground obstacles is effective for improving balance and gait ability of patients with stroke. However, it was more effective for the aquatic group than for the ground group.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.196-209
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• 2003

본 연구의 목적은 보통 보행과 장애물 보행 시작시에 accuracy constraints, 즉 발꿈치 닿기(swing limb heel-strike)의 정확도가 힘판(forceplate) 상에서 힘의 조절 (force modulation)과 EMG에 어떠한 영향을 미치는지를 분석하는 것이다. 본 실험의 대상자는 힘판(forceplate)위에서 보통 보행과 장애물 보행을 하되, 대상자 앞에 놓인 표적(target)에 정확히 발꿈치 닫기 (heel-strike)를 하도록 유도되었다. 이 때 힘판 자료와 전경골근(tibialis anterior)및 가자미근 (soleus)의 근전도 (EMG)의 활동을 양쪽 다리에서 측정하였다. 대상자 앞에 놓인 표적 (target)에 정확한 발꿈치 닫기(heel-strike)가 요구되었을 때에는 발끝밀기(swing toe-off) 시간이 증가되었으며 힘판(forceplate)상에서의 peak farce와 slope to peak force 가 감소되는 것으로 나타났다. 전경골근 (tibialis anterior)의 활동역시 큰 차이로 감소하는 것으로 나타났다. 하지만 보통 보행과 장애물 보행시의 근전도 혹은 힘판상의 자료에는 큰 차이점이 없는 것으로 나타났다. 이러한 결과는 기존의 상지(upper extremity)에서 보여준 운동제어 (motor control)의 이론들이 하지(lower extremity)에서도 동일하게 적용될 수 있음을 보여주는 것이다.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.30-37
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• 2003

Purpose : The purpose of this study is giving the healthy promotion and it's related data base for out-patients who had stroke via evaluating the general characters of their active daily living and physical therapy Method : This study researched 81 patients who had received physical therapy service in 6 general hospitals located Pusan city responded to the self-assessment questionnaires from July 2002 to August 2002. Conclusion : In this study, patients were composed of 61.7% of male, 65.4% of 50's-60's in the age, 56.8% of cerebral infarction, and 60.5% of right hemiplegia. 74.1% of patients received physical therapy after 6 months from an attack, only 62.9% used orthosis & gait aids, and 59.2% received medical care 2 or 3 times per week. 40.7% of patients had over 9 hours sleeping time and 22% had reduced $1{\sim}2hours$ before hospitalization. 90% did not have drinking and smoking. 91.4% had 3 times eating per day, and 67.7% did not have good nutrition. The reasons of that were their eating habit, 542% of eating-giver, 3.7% of economic problem. 46.9% of patients used healthy food. In active daily living, patients can't do drinking by cup, voiding & defication by themselves, however patients can't do wearing/take off, etiquette for dressing, bathing, stepping by themselves. 40.7% of patients don't wear orthosis, 55.6% of patients don't use W/C. Part of physical therapy that patients concerned importantly exercise for prevention of joint distortion, management of affected side, and 80% of patients was also concerned other's part, significantly. 71.8% of patients & care-givers want to receive physical therapy at home, and 74% of patients do physical therapy by themselves at home along teached hospitalization.

• Physical Therapy Korea
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• v.9 no.4
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• pp.1-11
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• 2002

본 연구의 목적은 이중과업 방법론(dual task methology)을 사용해서 젊은 사람과 노인을 대상으로 독립된 두 사건(two separate concurrent events)을 동시에 수행하는데 요구되는 주의력에 대한 분석과 노인에서의 특징적 차이를 찾는 것이다. 본 실험은 대상자가 힘판(force plate) 위에서 장애물(10cm) 보행시에 경피자극(cutaneous stimulation)에 대하여 마이크로 스위치(micro-switch)를 사용하여 반응하면서 시행되었다. 힘판과 시간(temporal events) 그리고 반응시간(reaction time)에 관한 자료들은 1000 Hz의 주파수로 수집되었다. 반응시간은 대상자들이 서 있는 상태(baseline) 장애물 보행시(dual task)에서 수집되었다. 반응시간은 아중과업 조건에서 대상자 모두에게서 긴 것으로 나타났으며 특히 노인에서 정상 성인보다 반응시간이 긴 것으로 나타났다. 이중과업 조건 하에서 노인 대상자가 정상 성인에 비해 발가락이 장애물에 닫지 않고 통과할 수 있는 공간, 즉 토우 클리어런스( toe-clearance)와 슬관전 굴곡(knee flexion) 각도가 훨씬 큰 것으로 나타났다. 이중과업 조건하에서 모든 대상자가 족관절 배측굴곡(ankle dorsiflexion) 각도를 감소시키는 것으로 나타났다. 노인들은 젊은 대상자들보다 훨씬 더 긴(124 ms) 유각시간을 보여 주었으며 정상 장애물 보행시 유각 시간은 이중과업보다 50 ms 긴 것으로 나타났다. 이러한 보행 특성의 차이는 노인대상자들이 젊은 대상자들보다 장애물 보행시에 이중과업의 영향을 더 받았기 때문인 것으로 판단된다. 이중 과업 시행시 이러한 토우 클리어런스의 감소와 장애물 통과시에 보행 속도의 증가는 아마도 낙상의 가능성을 증가시키는 요인이 될 수 있는 것으로 보여진다. 본 연구의 결과는 다중과업(multitasks)을 필요로 하는 보행 훈련 프로그램(gait training program)의 개발과 시행에 있어서 기초적인 자료를 제공할 수 있는 것으로 보여진다.