• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.2
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• pp.157-166
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• 1995

To investigate walkability of ramps, walking patterns of 18 healthy adults,12 aged 20 to 26 and 6 aged 68 to 76,were studied at free,rhythm constrained walking up or down ramp using goniometer and footswitch Ramp inclinations were set 4,8,12,16,20 degrees. The results were as follows. 1)The step length of subjects were decreased significantly in12$^{\circ}C$′or 16′free downramp walking. With regard to step length, some subject groups walked abnormally in 16" or 20" ramp walking 2) The step width of subjects were increased significantly in 12" or 16" ramp walking. 3) The cadence duration of some subject groups were increased in 12" upramp walking. 4) The double stance duration and double stance ratio of some subject groups were increased significantly in 8",12", or 16"upramp walking. 5) The maximum knee flexion angle of stance phase were increased in 12" ramp walking. 6)Most temporal parameters and spatial parameters of gait were increased or decreassd greatly between 4" ramp and 8" ramp or between 8′ramp and 12′ramp. But statistics significancy were not recognized 7) The results suggest that ramp inclination less than 8′(14%) -12′(21%) is desirable for the normal gait the ramp inclination must not exceed 16" -20" in unavoidable circumstances.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.2
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• pp.199-205
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• 2011

Purpose: The purpose of this study was to investigate the effect of 0cm, 2.5cm, 5cm height increase elevator shoes insole on gait and foot pressure Methods: Fifteen young adult were recruited this study. Gait and foot was measured by Gait AnalyzerTM(Tech Storm Inc. korea). Statistical analysis was used one-way ANOVA to know difference between 0cm, 2.5cm insole and 5cm insole Results: There was no significantly difference on foot length, foot width, foot angle, step time during gait. But step length and step width was significantly difference during gait. There was no significantly difference on gait ratio during stance phase. There was significantly difference on forefoot pressure and rearfoot pressure ratio. Conclusion: These results indicate that height increase elevator shoes insole may be caused step length, step width decreaseed during gait. It caused forefoot pressure increased and rearfoot pressure decreased on foot.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.161-169
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• 2008

The purpose of this study was to investigate kinetic variables of the lower extremity during walking on three different stair widths in healthy adults. Ten healthy college-aged adults($23.5{\pm}3.5$) recruited for this study. Each stairs with the same height and length(l8cm and 90cm) under the Korean Constructional Law but three different widths(26cm, 31cm and 36cm) were conducted for this study. One force plate(9286AA, Kistler Co.) was put on third stairs. One-way ANOVA was performed to find the stair width effects during stair walking and the following findings ware obtained. There was significantly decreased in ankle resultant joint moment at Pull-Up phase(p<.05) and, significantly increased in knee extension moment during mid-stance phase as stair width increase(p<.05), but there was no significance in ankle resultant joint moment was found at Forward Continuance Phase in Ascending Stair Walking and There was significantly increased in ankle resultant joint moment as stair width increase during mid-stance phase(p<.05) and no significance in knee and hip resultant moments among the stair width in descending stair walking.

• Korean Journal of Applied Biomechanics
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• v.26 no.1
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• pp.101-113
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• 2016

Objective: The purpose of this study was to investigate the effect of leg length discrepancy (LLD) on the human body during gait and standing posture. Methods: The study group comprised of 17 adult participants with LLDs of <1 cm. LLDs were artificially induced to 0, 1, 2, and 3 cm. The proportion of weight distribution, shift of the mean center of pressure, and Cobb's angle were measured in the standing position. Kinematic variables such as walking and striding width and time, and the proportion of stance phase for single- and double-limb gait were measured as well. The participants were required to either stand or walk on a treadmill (Zebris FDM) with a pressure plate, and the Cobb's angle measurements were obtained from radiographs. Results: A discrepancy of 3 cm in leg length resulted in a statistically significant shift of the center of pressure in the standing position. Moreover, the Cobb angle increased as the discrepancy became larger. The step length and width of the longer (left) leg during gait statistically significantly increased when the discrepancy was 2 cm. In addition, step time was statistically significant when the discrepancy between the longer (right) and shorter (left) legs was more than 2 cm. The proportion of single-limb stance phase was statistically significant as the discrepancy became larger, especially when the discrepancy was >2 cm for the longer (right) leg and 1 cm for the shorter (right) leg. Conclusion: The study showed that LLD influenced deformations of the human body and walking.

• Physical Therapy Korea
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• v.3 no.1
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• pp.1-11
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• 1996

The purpose of this study was to analyse the subtalar joint movement characteristics in human stance phase. The data of subtalar joint movement patterns are collected by CTA(calcaneus to tibia angle) measurements. CTA is defined as a angle formed between the bisect of the posterior shank and bisect of the posterior heel, as determined by placement of the retroreflective markers. The angle measured in degrees. The participants are 74 healthy individuals (37 men and 37 women) who have no orthopedic and neurological impairment, aged from 19 to 29 years(mean 22.95). Prior to participation, each subjecct informed the procedures of experiment from researcher and assistant researcher. The equipments of this study are walking grid, marking tapes, goniometer, video camera, monitor and ink for foot print are used in the study. In order to determine the statistical significance of result, the paired t-test and Pearson correlation were applied at the 0.05 level of significance. The results were as follows : 1. The reliability of measured CTA value are showed a high correlation, ranged from .86 - .94. 2. The mean value of step width are 7.67cm in men and 6cm in women. So, significant difference between men and women in 0.05 level of significance. 3. There was significant difference between man and women's TOA(toe out angle)(p<0.05). 4. The CTA of female's is more higher than male's one, however not statistical difference between man and women(p>0.05). 5. The CTA is reduced according to increasing TOA(p<0.05).

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.15-30
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• 2002

The purpose of this study was analyzed the effect of kinematical and kinetical factors of lower extremity of form change in the cause of growth an unborn child during in pregnancy. Three pregnant women were selected from pregnant 24 weeks as subjects. Each subjects were required to walk with usual walking speed. Cinematographic and GRF data were collected during walking, and the kinematical and kinetical variables were calculated using Kwon3d. Based on the results of the study, the following conclusions were drawn : 1. Step width and Step length The change of form during the period of pregnancy was not statistically found significant in the step width and the step length. 2. Angle of lower extremity 1) The change of form during the period of pregnancy was not statistically found significant in the hip angle at right heel contact, mid stance, but it was statistically found significant in the hip angle at toe off on p<.05. 2) The change of form during the period of pregnancy was not statistically found significant in the knee angle at right heel contact, mid stance, but it was statistically found significant in the knee angle at toe off on p<.05. 3) The change of form during the period of pregnancy was not statistically found significant in the ankle angle at right heel contact, mid stance, but it was statistically found significant in the ankle angle at toe off on p<.05. 3. Ground reaction force 1) The change of form during the period of pregnancy was statistically found significant in medial-lateral force(Fx) on p<.001. 2) The change of form during the period of pregnancy was not statistically found significant in post-anterior force(Fy). 3) The change of form during the period of pregnancy was statistically found significant in impulse force and minimum peak of vertical reaction force on p<.001, p<.01 but it was not statistically found significant in second maximum force.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.539-547
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• 2009

The purpose of this study was to investigate the changes of kinetic and kinematic parameters in obstacle gaits after 12 weeks of an aquatic exercise program. Eight female elders walked in four different heights of obstacles(0, 2.5, 5.1, & 15.2cm) on their self-selected speed. The ROM of hip was significantly increased after the aquatic exercise program. Swing and Stance duration were decreased. The step length was significantly increased and the step width was decreased. After the exercise program the clearance between the right foot and the top of obstacle(except 15.2cm) increased and the crossing speed was increased. The braking force, propulsive force, braking impulse, and propulsive impulse were significantly changed after the aquatic exercise program. The 12 weeks of the aquatic exercise program resulted in lower body strength and balance gains in female elders. The improvements were associated with changes in kinetic and kinematic parameters leading to an obstacle-crossing speed and a safer lower-limb control. The aquatic exercise program is suggested as an effective intervention to promote gait ability and prevent fall-related to the injuries.

• The Journal of Dong Guk Oriental Medicine
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• v.5
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• pp.79-95
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• 1996

When we see normal gait, gait cycle is seperated as stance phase and swing phase. It needs 6 determinant of gait of pelvic rotation, pelvic tilt, knee joint of stance phase, ankle and foot motion, ankle and knee motion, and pelvic movement to be accomplished. In addition, a joint and muscle action is accomplished biomechanically at the same time with its gait cycle. In oriental medicine, the relationships between chang-fu physiology and meridian physiology are summaried as follows ; ${\bullet}$ chang-fu physiology : Spleen manages the extremities. Liver manages soft tissues. Liver stores blood. Kidney stores essences. Kidney manages bones. ${\bullet}$ meridian physiology : The Leg Greater Yang Meridian and meridian soft tissues The Leg Yang-Myeong Meridian and meridian soft tissues The Leg Lesser Yang Meridian and meridian soft tissues The Leg Greater Yin Meridian and meridian soft tissues The Leg Lesser Yin Meridian and meridian soft tissues The Leg Absolute Yin Meridian and meridian soft tissues Especially, we can find out relations between in a "blood supplied feet can walk well" that explains "blood regulations and by liver nourishing effects"that is the closest concept of muscle. Abnormal gaits are due to three causes as following; first, physical defect secoud, pain third, nervous system or instability of muscle. In oriental medicine, we can know relationship in "atrophy, numbness, stroke, convulsion, muscular dystrophy of knee, rheumatoid arthritis, five causes of infantile growing defects, five causes of softening, sprain". Especially, atrophy is the most important symptom. Gait evaluation should be emphasized where a point can walk 8 feet to 10 feet considering stride width, stride length, the body weight center, stride number, flexion, extension, rotation of a joint as a standard factor. The point is we should find out something strange in a patient's side, front and back view. After that we should find out its cause as an index that we can observe abnormal findings in a joint and muscle.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.173-183
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• 2019

Objective: The aim of this study was to investigate the correlation coefficients between anthropometric parameters of the foot and kinetic variables during running. Method: This study was conducted on 21 healthy young adults (age: $24.8{\pm}2.1yes$, height: $177.2{\pm}5.8cm$, body mass: $73.3{\pm}7.3kg$, foot length: $256.5{\pm}12.3mm$) with normal foot type and heel strike running. To measure the anthropometric parameters, radiographs were taken on the frontal and sagittal planes, and determined the length and width of each segment and the navicular height. Barefoot running was performed at a preferred velocity ($3.0{\pm}0.2m/s$) and a fixed velocity (4.0 m/s) on treadmill (Bertec, USA) in order to measure the kinetic variables. The vertical impact peak force, the vertical active peak force, the braking peak force, the propulsion peak force, the vertical force at mid-stance (vertical ground reaction when the foot is fully landed in mid-stance or at the point where the weight was uniformly distributed on the foot) and the impact loading rate were calculated. Pearson's correlation coefficient was used to investigate the relationship between anthropometric variables and kinetical variables. The significance level was set to ${\alpha}=.05$. Results: At the preferred velocity running, the runner with longer forefoot had lower active force (r=-.448, p=.041) than the runner with short forefoot. At the fixed velocity, as the navicular height increases, the vertical force at full landing moment increases (r= .671, p= .001) and as the rearfoot length increases, the impact loading rate decreases (r=- .469, p= .032). Conclusion: There was a statistically significant difference in the length of fore-foot and rearfoot, and navicular height. Therefore it was conclude that anthropometric properties need to be considered in the foot study. It was expected that the relationship between anthropometric parameters and kinetical variables of foot during running can be used as scientific criteria and data in various fields including performance, injury and equipment development.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.7-14
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• 2002

In this study, a stress analysis is made fur an ankle foot orthosis (AFO) in the view point of structural stability. The investigated AFO is a solid and standard type. To analyze the stress distribution on the neck of AFO, the maximum AFO angular translation data is obtained by gait analysis. The material test of polypropylene is made to obtain the mechanical properties of AFO. The maximum dorsiflexion appears at the midstance in the gait analysis. The experimental angular translation at the top of AFO is about 10.3$^{\circ}$ at mid stance. Three models of AFO with different width of neck are made and analyzed with ABAQUS 6.1. The stress levels and distributions of 3 different width(W$_1$, W$_2$=0.85W$_1$, W$_3$=0.60W$_1$) AFO are investigated. As a result, the standard type(W$_1$) appears to the maximum stresses at the medial edge of cutout area surrounding ankle joint. The maximum stresses of the narrower type(W$_2$) are occured on medial edge and center of ankle. The narrowest type(W$_3$) appears to the maximum stresses at center of ankle. The maximum stresses become smaller as ankle width of AFO is narrower.