• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.594-601
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• 2019

A true MSEW abutment is an abutment type that directly supports the load of a superstructure. Metal strips, which are in-extensile reinforcements, should be used to minimize abutment deformation. A study to derive the application conditions of a True MSEW abutment was carried out by Zevogolis(2007). As a result, the pullout factor of safety of the uppermost reinforcement was estimated to be the smallest. Therefore, the pullout factor of safety of the uppermost reinforcement is the most important design factor. Parameter analysis was conducted with the abutment length, abutment heel, and abutment height as variables. The pullout factor of safety increased with increasing abutment length and abutment heel length. This is because the contact area increases and the superstructure is dispersed as the abutment length and abutment heel length increase. The pullout factor of safety converges at an abutment length of 1.2m and an abutment heel length of 0.9m. This is because the effective length of the reinforcement is reduced due to the increase in contact area. On the other hand, the extension of the superstructure will increase if the abutment length and abutment heel length are increased excessively. In addition, earth-volume is increased if the abutment height increases excessively. This acts as an upper load on the MSE wall. Therefore, it needs to be examined carefully.

• Journal of the Ergonomics Society of Korea
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• v.16 no.2
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• pp.61-71
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• 1997

In industrial designing of ready-to-wear shoes, one important factor to consider is that the population has diverse fooot shapes as well as foot length. The general shape of a foot could be represented by "foot ratio", i.e. the ratio of width to length. In this study, we measured several dey aspects of young Korean men's foot, and compared the results with their shoe sizes and general foot shapes. To this end, 172 male subjects were categorized according to their shoe size (small, medium, large) or foot ratio (wide, narrow, intermediate). The statistics of this survey indicated that the people with narrow foot shap have significantly greater foot length compared with the one having wide foot shape. Conversely, subjects having wide foot shape manifested significantly greater foot and ankle girth as well as significantly greater foot breadth. However, different foot shape groups showed no significant differences in heel width, heel ankle girth, instep height, and malleolus height. On the other hand, subjects wearing larger shoe size showed significantly larger foot measurements except instep and ankle heights, whereas subjects with shoe sizes 260 and below measured significantly more narrow heel and lateral metatarsal breadths. The deviation between foot length and dress shoe size(length) was greater in groups with wide foot shape and in groups wearing large shoe sizes. The results of this survey indicated that the subjects with wide foot shape apparently choose a size or two larger shoes for them as a compromise for a better breadth fit.eadth fit.

• Journal of the Ergonomics Society of Korea
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• v.35 no.1
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• pp.39-52
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• 2016

Objective: This paper investigates gait changes according to different heel heights and speeds, and the interaction between the effects of the heel height and the speed during walking on stride parameters and joint angles. Furthermore, the relationship among heel height, speed and gait variables is investigated using linear regression. Background: Gait changes by heel height or speed have been studied respectively, but has not been reported whether there is an interaction effect between heel height and speed. It would be necessary to understand how gait changes when a person wears heels in different heights at various speeds, for example, high-heeled walking at fast speed, since it may cause unusual gait patterns and musculoskeletal disorders. Method: Ten females were asked to walk at five fixed cadences (94, 106, 118, 130 and 142 steps/min.) wearing three shoes with different heel heights (1, 5.4 and 9.8cm). Nineteen gait variables were analyzed for stride parameters and joint angles using two-way repeated measure analysis of variance and regression analysis. Results: Both heel height and speed affect movement of ankle, knee, spine and elbow joint, as well as stride length and Double/Single support time ratio. However, there is no significant interaction effect between heel height and speed. The regression result shows linear relationships of gait variables with heel height and speed. Conclusion: Heel height and speed independently affect stride parameters and joint angles without a significant interaction, so the gait variables are linearly amplified or diminished by the two factors. Application: Walking in high heels at fast speed should be careful for musculoskeletal disorders, since the amplified movement of knee and spine joint can lead to increased moment. Also, the result might give insight for animators or engineers to generate walking motion with high heels at various speeds.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.397-406
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• 2013

PURPOSE: The Purpose of this study was on determine whether stair gait exercise and lamp gait exercise might increase the gait ability of the patients with stroke METHODS: Fourty five patients with stroke were randomly assigned to plane gait exercise group(n=15) and ramp gait exercise group(n=15) and stair gait exercise group(n=15). During four weeks, each group participated thirty minutes for five times per week. Subjects were assessed using pre-value and post-value measurement gait ability(Step length, Heel to heel base of support, Step time, Double support ratio, Gait velocity). RESULTS: These finding suggest that stair gait exercise group was significant in Step length, Heel to heel base of support, Step time, Double support ratio, Gait velocity(p<.05). And lamp gait exercise group was only significant increase in Step time, Gait velocity(p<.05). In comparison of three group, stair gait exercise group was high gait ability than other two groups(p>.05). CONCLUSION: This study showed stair gait exercise group can be used to improve gait ability than other two groups. Thus it indicates that the stair gait exercise group will be more improved through the continued gait program.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.3
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• pp.337-349
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• 1996

A study was conducted to find the possible relationship between slip distance and dynamic coefficient of friction (DCOF) through the biomechanical study of slips and falls using a broader variety of floors and levels of slipperiness than those used before. Four different floor surfaces covering the full range of floor slipperiness (with and without on oil contaminant) were prepared for ten subjects with each walking at a fixed velocity. The results showed that slip distance and heel velocity had a decreasing trend while stride length had a increasing trend as DCOF increased. The contaminant effect overpowered floor slipperiness effect because a higher DCOF surface with oil contaminant created longer slip distance than the lower DCOF with dry floor. Normal gait pattern and suggested heel velocity (10 to 20 cm/sec) were seen on dry floors but abnormally longer stride length and 5 to 10 times faster heel velocity were found an oily floors. In other words, faster heel velocity (greater than 10 to 20 cm/sec) is recommended to measure DCOF on oily floors because the assumption of normal gait was no longer valid.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.407-413
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• 2014

PURPOSE: We investigated the influence of heel insole and visual control on body sway index with high-heeled shoes. METHODS: The subjects of this study were 61 healthy students. None of the participants had any orthopedic or neurologic alterations. C90 area, C90 angle, trace length, sway average velocity were measured using a force plate by BT4. The variables were measured both with insole and without insole when wearing high-heeled shoes under the conditions of eyes open and eyes closed. The collected data were analyzed using the Kolmogorov-Smirnov test and paired t-test. RESULTS: When wearing high-heeled shoes with insole under the conditions of eyes open, trace length, C90 area, velocity were significantly more decreased than without insole (p<.01). When wearing high-heeled shoes with insole under the conditions of eyes closed, only C90 area was significantly more decreased than without insole (p<.05). When wearing high-heeled shoes with insole under the conditions of eyes open, trace length, C90 area, velocity were significantly more decreased than under the conditions of eyes closed (p<.01). CONCLUSION: The present study demonstrates that the use of high-heeled shoes with insole supported from heel to midfoot more increased static balance than without insole under the conditions of eyes open.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.1
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• pp.49-59
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• 2007

Objective : To purpose of this study was the most of the ladies wear high-heeled shoes at lease 4 to 5 day a week but the effect of it's height on the lumbo-sacral legion angle has not been clearly defined. Method : Subject were 20 young ladies, who had majored in physical therapy of the Dae-gu Health College. Method 1. PACS system X-ray was used to measure the lumbo-sacral legion angle under the condition of bare foot, 3cm, 7cm high-heeled at standing position. 2. Spinal Mouse was used to measure the spinal segment motion angle and length under the condition of bare foot, 3cm, 7cm high-heeled at being Flexion-Extension position Result : The result of this study were as follow I. Significant statistical increase in lumbar lordosis was observed as the heel height was increased from bare foot to 7cm high-heeled(p<.05), but there was no significant difference in the lumbo-sacral angle & sacral angle(p>.05). 2. The Height and the weight of the subjects, their preference on the shoes didn't affect the lumbo-sacral lesion angle(p>.05) 3. The variation of the heel height didn't affect the spinal segment motion angle and length(p>.05). Conclusion : There is strong relationship between the high of heel with increasing the lumbar lordosis(p<.05).

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.151-160
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• 2014

The purpose of this study was to investigate the GRF(ground reaction force) parameters according to the shoes's heel heights and ground landing distances during downward stairs on bus. Participants selected as subject were consisted of young and healthy women(n=9, mean age: $21.30{\pm}0.48$ yrs, mean height: $164.00{\pm}3.05cm$, mean body mass: $55.04{\pm}4.41kg$, mean BMI: $20.47{\pm}1.76kg/m^2$, mean foot length: $238.00{\pm}5.37mm$). They were divided into 2-types of shoe's heel heights(0 cm/bare foot, 9 cm) and also were divides into downward stairs with 3 types of landing distance(20 cm, 35 cm, 50 cm). A one force-plate was used to collect the GRF(AMTI, USA) data from the sampling rate of 1000 Hz. The GRF parameters analyzed were consisted of the medial-lateral GRF, anterior-posterior GRF, vertical GRF, loading rate, Center of Pressure(${\Delta}COPx$, ${\Delta}COPy$, COP area) and Dynamic Postural Stability Index(MLSI, APSI, VSI, DPSI) during downward stairs on bus. Medial-lateral GRF and vertical GRF didn't show significant differences statistically according to the shoe's heel heights and landing distance, but 9 cm shoes heel showed higher vertical GRF than that of 0 cm bare foot in landing distance of 50 cm. Also anterior-posterior GRF didn't show significant difference statistically according to the shoe's heel heights, but landing distance of 20 cm showed higher than that of landing distances of 35 cm and 50 cm in anterior-posterior GRF. Loading rate didn't show significant difference statistically according to the landing distance, but 9 cm shoe's heel showed higher than that of 0 cm bare foot during downward stairs. The ${\Delta}COPy$ and COP area didn't show significant differences statistically according to the shoe's heel heights and landing distance, but 0 cm bare foot showed higher than that of 9 cm shoe's heel in ${\Delta}COPx$. Dynamic Postural Stability Index(MLSI, APSI, VSI, DPSI) didn't show significant differences statistically according to the landing distance, but 9 cm shoe's heel showed decreased value than that of 0 cm bare foot in dynamics balance. Considering the above, parameters of GRF showed different characteristics according to the shoe's heel heights and ground landing distances during downward stairs on bus.

• Journal of the Korean Home Economics Association
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• v.34 no.2
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• pp.129-142
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• 1996

This paper pursues a comparative study on the design and function of the ready-made Bo-Son and the Bo-Son Pattern based on teaching and learning materials. It intends to investigate whether the Bo-Son is designed to suit to Kinetics of foot or to give the ease of wearing and taking off. The following results came out through trial wearing. 1) The Bo-Son pattern suggested in teaching materials can not satisfy the wearers with partial modification due to design problem. On the other hand, the ready-made Bo-Son can satisfy them with partial modification. 2) The important factor in designing the pattern of Bo-Son is the posture of foot when putting on it, that is, the height of the heel of the foot from the floor, the length of the heel, the length of toe and the bending angle of toe. 3) As a result of this study, in the design of the improved Bo-Son pattern, it is most suitable when the size of foot is 230mm, the height of the heel of the foot is 12.5cm, and and angle of the front toe of a sock is 35$^{\circ}C$.

• Journal of Korean Biological Nursing Science
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• v.13 no.2
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• pp.142-148
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• 2011

Purpose: The purpose of this study was to investigate the effects of aromatherapy massage in the elderly with knee osteoarthritis. Methods: Participants were assigned randomly to an intervention (n=21) group and a control (n=21) group. In order to increase a lasting effect of aromatherapy massage, an essential oil used in the form of cream. Each participant had aromatherapy massage on lower legs for 20 minutes each time twice a week for four weeks. Numerical rating scale was used for self-report of pain intensity. Sleep disturbance was measured by Korean Sleep Scale consisting of 15 items. Stride length had been obtained by measuring the distance from the heel of one foot to the heel of the other foot. Results: There was a significant difference between the pain scores of the experimental group and that of control group after the aromatherapy massage (p=.001). Whereas, no significant differences between sleep scores of the two groups (p=.592) was found. The experimental group's stride length significantly increased than those of the control group (p=.009). Conclusion: Aromatherapy massage could be recommended as an effective intervention to decease pain and to increase stride length in the elderly with knee osteoarthritis.