• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.467-475
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• 2001

The purpose of this study was to evaluate changes of static lumbar lordosis by different heel heights in normal adults and patients with herniation of nucleus pulposus(HNP). The lumbar lordosis was examined while standing on barefoot, on heel support with 4cm heel, and with 8cm heel in 10 normal adults and 10patients with HNP. Standing lumbar lateral view was performed by 20 minutes adaptation with corresponding shoe types. The angle of lumbar lordosis was taken with Wiltse and Winter's method(angles between upper margin of 1 st lumbar body and upper margin of 5th lumbar body). The results of this study were as follow: 1. Significant statistical decrease in lumbar lordosis was observed as heel heights were increased from barefoot to 8cm high heel in normal adults(p<0.05). 2. There were no significant differences in lumbar lordosis according to three different heel heights in patients with HNP(p>0.05). 3. In comparison of barefoot, There were statistically significant decrease in HNP patients compared with normal adults in terms of lumbar lordosis(p<0.05).

• Journal of the Korean Society of Safety
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• v.23 no.1
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• pp.35-45
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• 2008

This study was performed to compare the kinematics among three different safety shoes(type 1: ergonomically designed and high quality shoes, 2: curved and cushioned safety shoes, and 3: regular safety shoes) and to find the effect of insole during walking. Ten healthy subjects were recruited for this study. The range of motion of knee and ankle joint, angle of rear foot and angle of heel contact were measured using a three dimensional motion analysis system. In the second peak, the angle of heel contact showed statistically significant difference between safety shoes and insole, however, there was no statistical significance among three different safety shoes. The angle of ankle increased significantly at initial contact, first peak, the second peak and the toe off phase compared with type 1 and 2 safety shoes, and the angle of ankle showed statistically significant difference between with and without applying the insole. During the first peak, the second peak and the toe off phase, the angle of knee was statistical significance between safety shoes and insole. In heel contact, the angles of Achilles' tendon showed statistically significant difference between safety shoes and insole. The rear foot angles showed statistically significant difference between safety shoes and insole during heel contact and early heel contact. These results suggest that the type 1 safety shoes were superior to others in the statistics, and applying insole could be a possible method to prevent fatigue of lower extremity and musculoskeletal disorders. Further studies are needed to find the effect of ergonomically designed safety shoes and insole on practical value in prevention of musculoskeletal disorder, fatigue and satisfaction of workers.

• Journal of Biomedical Engineering Research
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• v.29 no.4
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• pp.316-322
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• 2008

The purpose of this study was to investigate muscle activation of lower extremity such as rectus femoris, tibialis anterior and soleus according to 0cm(bare foot), 4cm and 7cm heel height of shoe on the rocking surface in older women. 20 older women who did not have any lower musculoskeletal and neurological disorders in the past were participated in this study. Each subject was standing for 15 seconds on the level 8 of Biodex Stability System (BSS) while wearing 4cm and 7cm heel height shoes including bare foot. Electromyography was used to measure muscle activation of lower extremity, and the muscle activation was expressed as a percentage of maximal voluntary isometric contraction (% MVIC). We measured % MVIC of three muscles during 5 seconds except for the first 5 seconds and last 5 seconds. SPSS 12.0 program was used for this study. Repeated one-way analysis of variance(ANOVA) was performed to compare the significant difference among the muscles of lower extremities according to heel heights of shoe on the rocking plate. % MVIC of each muscle such as rectus femoris, tibialis anterior and soleus regarding heel heights of shoe had statistically significant differences (p<0.05). The results of contrast test were as follows; 1) % MVIC of rectus femoris had significant differences between barefoot and 4cm, and barefoot and 7cm. 2) % MVIC of tibialis anterior had significant differences between barefoot and 4cm, barefoot and 7cm, and 4cm and 7cm. 3) % MVIC of soleus had significant differences between barefoot and 7cm, 4cm and 7cm. The results indicate that all commonly responsive muscle on the conditions of barefoot, 4cm, and 7cm shoe height on the rcoking surface is tibialis anterior muscle. We found out that the more heels of shoe high, the more muscle activation increases. High-heeled shoes above 7cm remarkably increase the muscle activation of lower extremity and may result in muscle fatigue. Thus, these shoes may summate risk factors of falls in older women. We can acknowledge that the heels above 4 cm affect each muscle activation in lower extremity on the rocking surface.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.566-572
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• 2005

The most crucial factor in membrane LNG ships to ensure sage operations, is how to effectively control tank pressure at the time of excessive generation of boil off gas (BOG). When the ships carry out tank cool down with her retaining heel prior to arrival at loading port, the vessel encounters the critical situation of excessive BOG and high tank pressure that can lead to high degree of risk. This is to provide one of the best ways to secure safe and effective LNG ship operations focusing on the detailed methods of tank cool down to achieve ATR(Arrival Temperature requirement) without building up high tank pressure and excessive BOG and calculating the appropriate heel quantity to be unutilized for tank cool down and fuel during ballast voyage.

• Journal of the Ergonomics Society of Korea
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• v.32 no.3
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• pp.245-252
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• 2013

Objective: This paper analyzes the changes on stride parameters, joint angles, and trajectories of the body parts due to high heels during walking and explains the causal relationship between the changes and high heels. Background: This study aims to indicate the comprehensive gait changes by high heels on the whole body for women wearing high heels and researchers interested in high-heeled walking. Method: The experiment was designed in which two different shoe heel heights were used for walking (1cm, 9.8cm), and twelve women participated in the test. In the experiment, 35 points on the body were tracked to extract the stride parameters, joint angles, and trajectories of the body parts. Results: Double support time increased, but stride length decreased in high-heeled walking. The knee inflexed more at stance phase and the spine rotation became more severe. The trajectories of the pelvis, the trunk and the head presented outstanding fluctuations in the vertical direction. Conclusion: The double support time and the spine rotation were changed to compensate instability by high heels. Reduced range of motion of the ankle joint influenced on the stride length, the knee flexion, and fluctuations of the body parts. Application: This study can provide an insight of the gait changes by high heels through the entire body.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.206-213
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• 2020

The purpose of the study was to compare the differences among phases accoring to the gait time on the heel height during gait, investigate the effect on ROM of the lower limb on gait time. Ten female college students in their 20s participated in the study, and variables were calculated through 3D gait analysis on height of heel. As a statistical method, one-way ANOVA was performed for the differences between the three heel heights, and multiple regression analysis was performed to determine the effect of gait time on the ROM. As a result of the study, phase 2, the higher the heel, the longer the gait time, but phase 3, the higher the heel, the shorter the gait time. As a result of analyzing the effect of gait time on the ROM of the lower limb, in phase 2, the greater the ROM for the ankle and knee joint in 1 cm, and for the ankle joint in 5 cm, the longer the gait time. In phase 3, the greater the ROM for the hip joint in 1 cm, the longer the gait time, and the smaller the ROM for the ankle joint in 10 cm, the longer the gait time. Therefore, in the case of high-heeled shoes, it is suggested that the control of the ankle joint is important.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.479-486
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• 2010

The purpose of this study was to determine the effects of high-heeled shoe on the quiet standing and gait balance. Twenty women (mean height: $161.6{\pm}3.3\;cm$, mean body mass: $53.8{\pm}6.3\;kg$, mean age: $23.8{\pm}2.7$ yrs..) who were without history or complain of lower limb pain took part in this study. They were asked to stand quietly on a force platform for 30 sec and walk on it at their preferred walking speed (mean speed $3.14{\pm}0.5\;km/hr$.) with wearing three different high-heeled shoe, 3, 7, 9 cm high for collecting data. Data were randomly recorded to collect two trials for quiet standing and five trials for walking The parameters to have been analyzed for comparison between three conditions of the height of high-heeled shoe were COP(Center of Pressure) range, COP velocity, sway area, and free moment on the static balance and COP range, COP velocity, and free moment on the dynamic balance. In this study, high-heel height affected on the COP range and velocity in the ante-posterior direction during walking, dynamic balance, but didn't affect on the quiet standing, static balance.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.3
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• pp.271-278
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• 2014

PURPOSE: This study researched the effects of different types of high heels on the muscles surrounding the cervical spine, the thoracic spine, and the lumbar spine by analyzing muscle activation of the paraspinal muscles during walking while wearing high heels. The high heels were all of the same height: 8cm. METHODS: The 28 subjects in this experiment were females in their 20s with a foot size of 225-230mm. To measure the muscle activation of the paraspinal muscles, EMG electrodes were attached on the paraspinal muscles around C6, T7, and L5. The muscle activation during walking while wearing 8cm high wedge heels, setback heels, and french heels was measured. The measurements were performed 3 times each and the mean value of the result was used for analysis. Two kinds of velocity were used in this study. One of the velocity was 2.5 m/s. The other was 3.5 m/s. RESULTS: The muscle activation of paraspinal muscles increased significantly according to increase of walking velocity. But there was no significant difference according to the heel types. CONCLUSION: In view of the results, the height of heels and the velocity of walking are more convincing variables than the width of the heels on the muscle activation of paraspinal muscles. So wearing high heels is not recommended for those who have pain or functional problem of cervical and lumbar vertebrae.

• Journal of the Ergonomics Society of Korea
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• v.24 no.4
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• pp.23-30
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• 2005

The mailman's shoes should be designed in due consideration of occupational features they spend most of times to walk. For that reason, the shoes required functions to reduce the foot fatigue and to protect body by dispersing the body weight to the whole foot. In this research, for the functional improvement of the insole, insoles are investigated and analyzed by biomechanics experimentation. Under the base of these experimental results, we develop insoles that can reduce the body load and muscular-skeletal disorder. The pressures are concentrated on the metatarsus and heel by the result of analyzing pressure distributions of the using shoes. Accordingly, we offer the prototype functional insole that is ranked from high pressure to low pressure on the base of a shock absorb function. This prototype functional insole is examined for statistical significance by pressure distribution areas. The experimental results show that pressure areas are dispersed to whole foot, for this reason, pressures of the metatarsus and heel are reduced. Results of this research can not only improve the function of insoles which is suitable for occupational features, but also be a base on constructing data bases for biomechanics gait insoles.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.33-36
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• 1998

This study was carried out to examine the effects of cutting dates and rooting promoters on rooting of the Rhododendron mucronulatum Turcz. The rooting percentage in greenwood cutting was high in June and decreased after July 3, when reproductive growth began. The best rooting percentage(92.5%) occurred when cutting was completed on June 12. There was no difference in rooting potentials between the greenwood straight cutting and the greenwood heel cutting. Cuttings of R. mucronulatum for. albiflora showed high rooting percentage(85%) similar to the cuttings of R. mucronulatum. Dipping cuttings in NAA $2,000mg{\cdot}L^{-1}$ solution for 15 sec increased the rooting percentage up to 97.5%, and also promoted root growth.