• Physical Therapy Korea
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• 제20권1호
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• pp.64-73
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• 2013

The purposes of this study were to develop a new orthosis controlling ankle and knee joint motion during the gait cycle and to identify the effects of the newly designed orthosis on gait kinematics and tempospatial parameters, including coordination of the extremities in stroke patients. Fifteen individuals who had sustained a stroke, onset was 16 months, participated in this study. Before application of the measurement equipment the subjects were accustomed to walking on the ankle-foot orthosis (AFO) or stance control knee with knee flexion assisted-oil damper ankle-foot orthosis (SCKAFO) for 5 minutes. Fifteen patients were investigated for 45 days with a 3-day interval between sessions. Measurements were walking in fifteen stroke with hemiparesis on the 3D motion analysis system. Comparison of AFO and SCKAFO are gait pattern. The difference between the AFO and SCKAFO conditions was significant in the gait velocity, step length of the right affected side, stance time of both legs, step-length asymmetry ratio, single-support-time asymmetry ratio, ${\phi}$-thigh angle and ${\phi}$-shank angle in the mid swing (p<.001). Using a SCKAFO in stroke patients has shown similar to normal walking speeds can be attained for walking efficiency and is therefore desirable. In this study, the support time of the affected leg with the SCKAFO was longer than with the AFO and the asymmetry ratio of single support time decreased by more than with the AFO. This indicates that the SCKAFO was effective for improving gait symmetry, single-support-time symmetry. This may be due to the decrease of gait asymmetry. Thus, the newly designed SCKAFO may be useful for promoting gait performance by improving the coordination of the extremity and decreasing gait asymmetry in chronic stroke patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제16권7호
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• pp.4689-4696
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• 2015

The purpose of this study was to evaluate biomechanical characteristics of trekking shoes using 3D Bootie method as mimics barefoot form of F Co. that provides the best comfort and plantar pressure dispersion. The control group is normal trekking shoes of M Co. and K Co.. 13 healthy males measured the foot pressure, EMG and GRF. Collected data was analyzed using One-way ANOVA in order to investigate the effects of each trekking shoes. The results are as follows: Trekking shoe of F Co. was significantly wider in contact area than others at MF and significantly lower in maximum force, peak pressure than others at RF. In the case of muscle activity, acted in the same way as the effect of barefoot walking. In the case of GRF, effectively absorbed the impact force, so it is possible to efficient walking. As a result of the analysis, trekking shoe using of 3D Bootie method of F Co. can be efficient walking by reducing the load of foot during walking.

• Korean Journal of Applied Biomechanics
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• 제25권2호
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• pp.183-190
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• 2015

Objective : Walking with a Material handling is an activity frequently undertaken by agricultural workers in Korea, due to the nature of their work. This study aimed to investigate differences in biomechanical variables according to the mechanical alignment of the lower limbs when walking with a heavy load, and to use this as basic data in the design of various working environments to reduce the skeletomuscular burden on the knee joint. Method : The study subjects comprised of 22 right-foot dominant adult men and women aged between 20 and 23 years. The subjects were divided into a varus or valgus group according to the mechanical alignment of the lower limb by using radiographic findings. The subjects walked without any load and with a load of 10%, 20%, or 30% of their body weight held in front of them. The Kwon3d XP program was used to calculate biomechanical variables. Results : The flexion/extension moment of the knee joint showed a decreasing trend with increased load, irrespective of the mechanical alignment of the lower limb, while the varus group did not show normal compensatory action when supported by one leg at the point of maximum vertical ground reaction force. In addition, in terms of the time taken, subjects showed no difficulties in one-foot support time up to 20%/BW, but at 30%/BW, despite individual differences, there was an increase in single limb. The increased load resulted in a decrease in the ratio of standing phase to ensure physical stability. The valgus group showed a trend of increasing the stability of their center of mass with increasing load, through higher braking power in the early standing phase. Conclusion : In conclusion, although there was no statistical difference in biomechanical variables according to the mechanical alignment of the lower limbs, the varus group showed a more irregular walking pattern with a Material handling than the valgus group, partially proving the association between lower limb alignment and walking with a Material handling.

• Journal of the Korean Society of Marine Environment & Safety
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• 제22권1호
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• pp.74-81
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• 2016

Because most of the passengers are not accustomed with onboard environments, it is very important to analyze and predict the behaviors' characteristics of passengers under disasters' conditions, and apply those results for making countermeasures. On this view point, this study focused on the walking characteristics of onboard-novices are tested and analyzed under blackout condition that has high possibility to happen. As a result, comparing to under normal lighting conditions, the waking times under blackout conditions are 155.8~247.1 % longer on full path, 56.9~331.7 % on corridors, 75.3~152.9 % on stairs, respectively. And under the same blackout conditions, walking times in cases of the exit guidance marks being attached on top side of walls saved times, like 21.6~24.0 % on full path, 37.7~58.9 % on corridors, 18.7~19.2 % on stairs, comparing to the cases of exit guidance marks being not attached. On the other hand, after tests under without exit guidance marks, 60.7% among respondents answered that internal structures like wall/stair (35.7 %) and handrail (25 %) are very helpful to decide way findings, and 28.6 % selected personal instincts is important. But 50 % responded that exit guide marks are effective to find ways, after the tests under with exit guidance marks.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권9호
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• pp.20-28
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• 2019

This study comparatively analyzes general walking shoes on the conical top foundation of the ground condition and the pressure distribution during walking with shoes that are currently under development. Two categories of footwear were used: general footwear and a footwear conical top foundation that is currently under development. Experiments were carried out on hard ground and sandy soil in 15 male twenties that satisfy the conditions of normal foot wearing 260 mm. The pressure during walking was measured using Techstorm's Wireless Insole System, and foot pressure was measured in 7 zones of the foot. Studies have shown different maximum forces, average pressures, and pressure distributions depending on the shoe and ground conditions. This study shows that shoes with general low pressure dispersion effects depending on the feet in hard ground and sand ground are different from shoes with the conical top foundation that is currently under development. It is expected that it will be useful for the development of shoes that can be worn in all hard ground and sandy ground by selecting various rubber materials through further research.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권9호
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• pp.56-65
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• 2019

This study empirically analyzes the effect of weather on pedestrian volume in an urban space. We used data from the 2009 Seoul Flow Population Survey and constructed a model with the pedestrian volume as a dependent variable and the weather and physical environment as independent variables. We constructed 28 models and compared the results to determine the effects of weather on pedestrian volume by season, land use, and time zone. A negative binomial regression model was used because the dependent variable did not have a normal distribution. The results show that weather affects the volume of walking. Rain reduced walking volume in most models, and snow and thunderstorms reduced the volume in a small number of models. The effects of the weather depended on the season and land use, and the effects of environmental factors depended on the season. The results have various policy implications. First, it is necessary to provide semi-outdoor urban spaces that can cope with snow or rain. Second, it is necessary to have different policies to encourage walking for each season.

• Therapeutic Science for Rehabilitation
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• 제12권4호
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• pp.111-122
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• 2023

Objective : To identify the effect of lifestyle risk factors on the daily activities and cognition of the older adults in the community using the National Health Insurance Corporation 2015 geriatric cohort database. Methods : Lifestyle risk factors were defined as body mass index (BMI), smoking, drinking, vigorous exercise, moderate exercise, and walking, and basic and instrumental activities of daily living (ADL) and cognitive function variables were included in the analysis. ADL and cognitive function according to sex and age were analyzed using a t-test and one-way ANOVA. The correlation between lifestyle risk factors, ADL, and cognitive function was analyzed using Pearson's correlation analysis, and multiple regression analysis was performed to analyze their influence. Results : The factors affecting basic ADL (BADL) were sex and walking exercises, with an explanatory power of 1.7%. Instrumental ADL (IADL) included age, drinking, and walking exercises, with an explanatory power of 2.6%. Cognitive function included sex, age, BMI, vigorous exercise, and walking, with an explanatory power of 5.3%. Conclusion : Lifestyle risk factors partially affected BADLs/IADLs and cognitive function in community-dwelling older adults. This suggests the need to systematically manage lifestyle risk factors to improve and maintain the healthy lives of older adults facing biological aging.

• Journal of Biomedical Engineering Research
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• 제19권1호
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• pp.69-80
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• 1998

This research was designed to investigate how the exercise program affects paraplegic standing and walking employing functional electrical stimulation(FES). Emphasis was also given to fatigue of major lower extremity muscles induced by different types of electrical stimulation. We applied continuous and intermittent rectangular pulse trains to quadriceps of 10 normal subjects and 4 complete paraplegic patients. The frequencies were 20Hz and 80Hz, and the knee angle was fixed at 90$^{\circ}$and 150$^{\circ}$to investigate how muscle fatigue is related to muscle length. The knee extensor torque was measured and monitored. We have been training quadriceps and gastrocnemius of a male paraplegic patient by means of electrical stimulation for the past two year. FES standing was initiated when the knee extensors became strong enough to support the body weight, and then the patient started FES walking utilizing parallel bars and a walker. We used an 8-channel constant-voltage stimulator and surface electrodes. The experimental results indicated that paralyzed muscles fatigued rapidly around the optimal length contrary to normal muscles and confirmed that low frequency and intermittent stimulation delayed fatigue. Our exercise program increased muscle force by approximately 10 folds and decreased the fatigue index to half of the initial value. In addition, the exercise enabled the patient to voluntarily lift each leg up to 10cm, which was of great help to the swing phase of FES walking. Both muscle force and resistance to fatigue were significantly enhanced right after the exercise was applied every day instead of 6 days a week. Up to date, the patient can walk for more than two and half minutes at 10m/min while controlling the on/off time of the stimulator by pushing the toggle switch attached to the walker handle.

• Journal of rehabilitation welfare engineering & assistive technology
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• 제8권4호
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• pp.305-312
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• 2014

In this study, in order to quantitatively confirm walking rehabilitation degree, we analyzed EMG pattern simulated abnormal gait and normal gait by applying a curve fitting. We calculated the suitable high-order function for EMG signal, and classified them into 5 groups by using cluster analysis. Depending on the distance from normal pattern group, we listed the pattern group and then the distribution of each variables were confirmed. The amplitude-decreased pattern was the most similar to the normal pattern, but the reversed pattern showed the lowest similarity. Due to the smaller overlapping range, the distribution of the groups were possible to classify using the value of variable. The standard deviation of each term coefficient was compared to indicate the quantitative rehabilitation extent, and the higher value was confirmed as the pattern is close to the normal pattern. Consequently, the representation of quantitative rehabilitation extent is expected to contribute to the more effective rehabilitation method study.

• Journal of Korean Physical Therapy Science
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• 제11권3호
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• pp.28-37
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• 2004

Background: Lumbar joint dysfunction is reported to be the main cause of lower back pain (LBP). The purpose of this study was to evaluate the effect of joint dysfunction on the postural balance of the lower hack and pelvis in different normal activities such as walking or stair management. Also it was studied whether the status of LBP (intensity and duration of LBP, length of treatment) contributes to die pelvic height difference (PHD) in various postures. Subjects: 28 patients with LBP and 32 normal adult volunteers, 60 years of age or younger, who came to the Community Health Center and orthopedic clinics in Incheon, South Korea. Methods: In order to determine the accuracy of the manual angulometer method in measuring the PHD, it was compared to the pelvic x-ray method in selected subjects. In the manual angulometer method, the arm of the angulometer was placed on the top of both iliac crests. The PHD was measured in static upright stance, then one-legged stance, on the affected leg or unaffected leg each time. Information regarding the disease status was obtained through interviews. Visual assessment scale was used to grade the intensity of LBP. Data analysis was performed using SPSS 10.0/PC program. Homogeneity between the two groups was tested by 2-test and t-test. To compare the PHD of the subgroups, we used t-test, F-test and two-way ANOVA. Relationships among dependent variables were analyzed by Pearson correlation analysis. Conclusion: In patients with LBP, lumbar joint dysfunction causes lumbar and pelvic postural asymmetry during normal activities.