• Structural Engineering and Mechanics
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• v.71 no.3
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• pp.245-255
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• 2019

In this paper, an inverted-pendulum model consisting of a point supported by spring limbs with roller feet is adopted to simulate human walking load. To establish the kinematic motion of first and second single and double support phases, the Lagrangian variation method was used. Given a set of model parameters, desired walking speed and initial states, the Newmark-${\beta}$ method was used to solve the above kinematic motion for studying the effects of roller radius, stiffness, impact angle, walking speed, and step length on the ground reaction force, energy transfer, and height of center of mass transfer. The numerical simulation results show that the inverted-pendulum model for walking is conservative as there is no change in total energy and the duration time of double support phase is 50-70% of total time. Based on the numerical analysis, a dynamic load factor ${\alpha}_{wi}$ is proposed for the traditional walking load model.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.27-36
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• 2007

The purpose of this study was to investigate the effect of the upper body in order to increase a propulsive force in the old's walking. The subjects were each 10 males, the latter term of the aged and former term of the aged. There were three walking speeds of slow(about 5km/h), medium(about 6km/h), and maximum speed(about 7km/h). The subjects walking 11m were filmed the 5m section (from 3m to 8m) by 2-video cameras using three dimensional cinematography. And we computed different mechanical quantities and especially computed the relative momentum in order to achieve this study's aim. In this study, we was able to acquire some knowledge. The step length and step frequency increased in proportion to the walking speed, and the faster walking speed, the shorter ratio of supporting time( both legs supporting time/one step length time). When it was one leg support phase, the torso was indicated to generate the momentum in order to produce the propulsive force of walking. The upper and lower body had a cooperative relation for walking such as keeping step rate with the arms to legs and maintaining the body balance. The opposition phase for upward-and-downward direction of the torso and arms in walking was functioned to prevent the increase rapidly toward vertical direction of the center of gravity. The arms had contributed to coordinate the tempo of legs and the posture maintenance of the upper body. And by absorbing the relative momentum from the upper torso with arms to the lower torso, it had the rhythmical movement on upward-and-downward direction reducing the vertical reaction force. On account of the relations of absorption and generation of the propulsive force and the production of vertical impulse in the lower torso when walking by maximum speed, it was showed that the function of lower torso was come up as important problem for the mechanical posture stability and propulsive force coordination.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.189-195
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• 2012

Parcel delivery services are a bit different from general vehicle routing problems since the services require a deliver's walking time to give the parcel to the customer. This time takes more than 1/4 of total delivery time, but it is ignored for the convenience of algorithm design in general. The walking time is too big to be ignored if we need to estimate necessary delivery time precisely as much as possible, or to design a heuristic with varying vehicle moving speeds in metropolitan area. For these reasons, the walking times are surveyed and analyzed to use on the design of VRP heuristic for parcel delivery services in this research.

• Physical Therapy Korea
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• v.20 no.4
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• pp.55-64
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• 2013

The first purpose was to identify the plantar pressure distributions (peak pressure, pressure integral time, and contact area) during level walking, and stair ascent and descent in asymptomatic flexible flatfoot (AFF). The second purpose was to investigate whether peak pressure data during level walking could be used to predict peak pressure during stair walking by identifying correlations between the peak pressures of level walking and stair walking. Twenty young adult subjects (8 males and 12 females, age $21.0{\pm}1.7$ years) with AFF were recruited. A distance greater than 10 mm in a navicular drop test was defined as flexible flatfoot. Each subject performed at least 10 steps during level walking, and stair ascent and descent. The plantar pressure distribution was measured in nine foot regions using a pressure measurement system. A two-way repeated analysis of variance was conducted to examine the differences in the three dependent variables with two within-subject factors (activity type and foot region). Linear regression analysis was conducted to predict peak pressure during stair walking using the peak pressure in the metatarsal regions during level walking. Significant interaction effects were observed between activity type and foot region for peak pressure (F=9.508, p<.001), pressure time integral (F=5.912, p=.003), and contact area (F=15.510, p<.001). The regression equations predicting peak pressure during stair walking accounted for variance in the range of 25.7% and 65.8%. The findings indicate that plantar pressures in AFF were influenced by both activity type and foot region. Furthermore the findings suggest that peak pressure data during level walking could be used to predict the peak pressure data during stair walking. These data collected for AFF can be useful for evaluating gait patterns and for predicting pressure data of flexible flatfoot subjects who have difficulty performing activities such as stair walking. Further studies should investigate plantar pressure distribution during various functional activities in symptomatic flexible flatfoot, and consider other predictors for regression analysis.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.21 no.4
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• pp.370-379
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• 2014

Purpose: The purpose of this study was to identify the time for young adults to reach resting blood pressure after walking as measured by an automatic and a mercury sphygmomanometer. Methods: Participants were 33 nursing students in their 20s. Blood pressure after walking was measured every minute on both arms simultaneously for a total of 6 times after walking for 12 minutes on a treadmill at ratings of perceived exertion (RPE) of 11. Data were analyzed using paired t-test, Bland-Altman plots and repeated measures ANOVA. Results: Systolic blood pressure after walking was the same as measurements corresponding to resting blood pressure after 3 minutes of resting if measured with the automatic sphygmomanometer and 4 minutes of resting if measured with the mercury sphygmomanometer. Conclusions: In order to measure the resting blood pressure for healthy young adults who performed low-density walking for 12 minutes on flat land, the measurement needs to be made after a resting time of at least 3 minutes in the case of an automatic sphygmomanometer and 4 minutes in the case of a mercury sphygmomanometer.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.137-145
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• 2020

Purpose: The purpose of this study is to examine the effect of various bridge exercises on walking ability. Method: The subjects were 30 stroke patients. They were divided into a bridge exercise group on a stable support surface (Group I), a bridge exercise group on an unstable support surface (Group II), and a bridge exercise group combined with whole body vibrations (Group III). 10 subjects were randomly assigned into each group. The subjects of this study had 30 minutes of nervous system physical therapy including gait training and strength training. In addition, each group underwent a 30 minutes session five times a week for eight weeks. Before intervention, LUKOtronic was used to measure step width and step length, time was measured with a 10 m walking test, and time and number of steps were measured with the figure 8 walking test. After the intervention, remeasured and analysis was performed for each group. Results: As a result of comparing and analyzing the change of walking ability between groups, there was a statistically significant difference. As a result of the post hoc analysis according to the change of walking ability among groups, the change of walking ability was larger in Group III than in Group I and Group II. Conclusion: Based on these results, it is confirmed that the bridge exercise combined with whole body vibration was more effective for walking ability. Based on these findings, this study proposes an effective program for elite athletes as well as stroke patients.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.2 no.1
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• pp.83-92
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• 2004

This study aims to the influenced factor analysis of spinal cord independence measure(SCIM), on walking velocity, walking endurance, time up & go(TUG), and subject characteristics. The subject of this study were 12 persons with incomplete spinal cord injury(ASIA C, D). All subject ambulatory with or without an assistive device. All participants were assessed on SCIM(score), walking velocity(m/s), walking endurance(m) and TUG(s). The data were analyzed using independent t-test and stepwise multiple regression. The results revealed that no statistical difference was noted in subject characteristics among SCIM, walking velocity, walking endurance, TUG(p>0.5). The independence score, breathing-sphincter control and ambulation were important factors in TUG(31.4%). The results suggest that SCIM may be an inappropriate assessment tool to predict gait ability of patient with incomplete spinal cord injury. Further study about gait speed, gait endurance and TUG by change of SCIM is needed using to patient of incomplete spinal cord injury.

• PNF and Movement
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• v.16 no.1
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• pp.93-103
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• 2018

Purpose: The aim of this study was to investigate the effect of goal-oriented side walking training on balance and gait in chronic stroke patients. Methods: This study involved 18 chronic stroke patients who were divided into an experimental group (n=9) and a control group (n=9). The experimental group performed goal-oriented side walking training, and the control group performed general side walking training. The walking variables assessed were walking speed, stride length, and 10-m walking time. The balance variables assessed were foot pressure, timed up and go test (TUG), and Berg balance scale (BBS). These variables were measured before and after the exercise. Wilcoxon's signed-rank test was used to compare the participants' performances before and after the intervention in both groups. The Mann-Whitney U test was conducted for between-group comparisons after the intervention. Statistical significance was set at ${\alpha}=0.05$ Results: Walking speed, stride length, 10-m walking time, TUG, and foot pressure were significantly improved in both groups after the exercise (p<0.05). The between-group comparison showed a significant improvement in the goal-oriented side walking group (p<0.05). However, there were no significant between-group differences in 10-m walking times (p>0.05) and BBS (p=0.05). Conclusion: The results revealed that goal-oriented side walking training was effective in improving the balancing and walking ability of chronic stroke patients.

• PNF and Movement
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• v.9 no.2
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• pp.29-37
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• 2011

Purpose : The purpose of this study was to find out of an effect of forward, backward walking using partial weight bearing on walking of the patient with incomplete spinal cord injury. Methods : The average age, and the term of being sick of 6 patients who were selected as the subjects with incomplete spinal cord injury and who received medical attention in the National Rehabilitation Hospital, was 50.3 years old, and 10.7 months, and those were also the patients that were classified as ASIA-C or D by ASIA. The forward, backward walking using a partial weight bearing system as the research method, took total 6 weeks, 3 days per week, 3 times per day, total 45 minutes for each time(15 minutes for a time, 5 minutes for a breathing time), and the 15 minutes was used for forward walking 7.30 minutes, backward walking for 7.30 minutes, to find out before and after the test of WISCI, PCI, Walking Speed, Motor Score of Lower Limbs for the selected patients with incomplete spinal cord injury. Results : The result was showed WISCI from 17 points to 17 points that is, no change occurred at all, and PCI from $161.01{\pm}103.06$ to $74.97{\pm}58.19$, some amount of reduction that is not statistically significant(p<.05). Regarding walking speed, it increased from $24{\pm}.07m/sec$ to. $61{\pm}.35m/sec$, that is statistically significant(p<.05), and motor score of lower limbs showed statistically significant increase like from $33.17{\pm}7.08$ to $37{\pm}5.14$(P<.05). Conclusion : The 4 evaluation categories seem to have shown differences due to an insufficient number of subjects, and short test term, and it seems the more diverse task-oriented walking exercises should be studied in the coming days.

• Journal of Korean Clinical Health Science
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• v.5 no.1
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• pp.816-824
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• 2017

Purpose. This study was classified into normal and demented elderly through K-MMSE. The purpose of this study was to analyze gait characteristics of normal elderly and demented peoples using GAITRite walking system. Methods. The subjects of this study were selected as elderly people receiving home visit physical therapy. An independent t-test was conducted to verify the statistical significance of the time-space variables of the elderly with dementia. Results. Step time(p=0.041), cycle time(p=0.037), distance(p=0.024), and cadence(p=0.048) were significantly shorter in the normal elderly than in the demented elderly on flat place. The mean age was significantly longer in normal elderly than in elderly persons with dementia. Step time(p=0.022), cycle time(p=0.023), distance(p=0.019), and cadence(p=0.015) were significantly shorter in the mat walking. The mean age was significantly longer in normal elderly than in elderly patients with dementia. Stretch time, cycle time, distance, and hair support time were significantly shorter in the mat walking. The mean age of the elderly was significantly longer than that of the elderly with dementia. The spinal support time, which is a spatial variable, was significantly shorter in the normal elderly than in the demented elderly. Conclusions. It compares the various gait characteristics of the normal and demented elderly people, thereby increasing the walking ability of the elderly person more effectively. This study should be utilized as basic data for preventing fall-down.