• Physical Therapy Korea
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• v.23 no.4
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• pp.27-37
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• 2016

Background: In previous studies regarding flexible pes planus, Foot orthosis, special shoes have been used as interventions for correcting malalignment and intrinsic muscles strengthening exercise have been regarded as interventions for foot function and supporting medial longitudinal arch during walking. However, some recent studies reported that strengthening extrinsic muscles as well as intrinsic muscles is more effective and active intervention for flexible pes planus. In particular, the tibialis posterior muscle of foot extrinsic muscles plays essential roles in maintaining the medial longitudinal arch during dynamic weight bearing and balance. In addition this muscle acts longer than other supination muscles during the stance phase in the gait cycle. Objects: This study aimed to investigate the effect of foot intrinsic muscle and tibialis posterior muscle strengthening exercise for plantar pressure and dynamic balance in adults with flexible pes planus. Methods: 16 young flexible pes planus adults (7 males, 9 females) were recruited and were randomized into two groups. The experimental group performed foot intrinsic muscle and tibialis posterior muscle strengthening training, the control group performed only foot intrinsic muscle strengthening training. All groups received strengthening training for 30 minutes five times a week for six weeks. Results: The experimental group had significantly lower plantar pressure of medial heel area than the control group in stand (p<.05). The experimental group had significantly higher dynamic balance ability than control group (p<.05). Conclusion: The results of this study provide evidence to suggest that foot intrinsic muscle and tibialis posterior muscle of extrinsic muscle strengthening exercises may improve plantar pressure distribution and dynamic balance ability in adults with flexible pes planus.

• Journal of Korean Academy of Nursing
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• v.18 no.1
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• pp.34-43
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• 1988

The present study has been undertaken to assess the electrical activity of right tibialis anterior, right gastrocnemius, right rectus femoris, right biceps femoris and right paralumbarvertebral muscles quantitatively by EMC while standing erect on the height of 0cm, 3cm, 5cm and 7cm heels. The inclinations of the heels were 0, 6, 11, 17 degrees, respectively. Foully young women ranging from 18 to 24 of age were examined. Electrical activity of various muscles while standing erect on the height of various heels were compared with that of 0cm heel. The results obtained were as follows : 1. Electrical activity of the tibialis anterior increased significantly as the height of heels became higher ; which was thought to be due to the effort to counteract the instability standing with high heels. 2. There was a significant increase in electrical activity of the gastrocnemius as the height of heels increased. It might be due to compensatory activity against shifting of the center of gravity forward. 3. There was a significant increase .in electrical activity of the rectus femoris and biceps femoris at the height of 3cm, 5cm and 7cm heels ; which seemed to be due to the effort to stabilize the knee joint. 4. Electrical activity of the paralumbarvertebral muscles increased significantly at the height of 5cm and 7cm heels ; which was considered to be due to the effort to prevent forward imbalance. From These results, it may be concluded that electrical activities of various postural muscles increase significantly while standing erect on the height of 3cm, 5cm and 7cm heels to counteract an instability of their posture and compensate the forward shifting tendency of the center of gravity.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.88-92
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• 2006

Large-scale model tests of welded topside joints were carried out to observe the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The fatigue crack behaviors for various loading conditions were measured and investigated around the critical joint sections. The experimental results have been verified with numerical approaches and also compared with the AWS D1.1 and DnV RP-C203 design curves. The large-scale experiment models were fabricated, based on the actual operating east area fixed platform. The dimensions of the models were slightly modified to accommodate the test facilities and capacities. The fatigue test was carried out having ${\Delta}Q$ of T1=705.6kN, T2=749.7kN and T3=793.8kN. The three specimens were statically loaded 20 times, with various loadings of about 50kN intervalsbetween the maximum and minimum loads required in the fatigue tests. This loading removed the residual stress in the specimen before the fatigue tests. The topside joint crack was initiated from the brace heel, where the maximum tensile stress occurred. The API 2W Gr.50 steel satisfied the AWS D1.1 detail category C and DnV RP-C203 detail category F ${\Delta}S-N$ curve.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.171-183
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• 2012

This research attempted to examine whether there were differences in preference for the shoes according to fashion lifestyle and age by conducting survey on 200 women of 20s and 40s among the adult women who were expected to have interest in not only functionality but also aesthetic aspects of shoes. First, the results of comparing the preferences according to fashion lifestyles showed that those who pursued practical group preferred loafer, strap shoes, and baggy boots, indicating that they preferred low and comfortable shape of shoes which are easy to put on/take off and easy to coordinate with any clothes. Those who pursued personality group and ostentation group were more sensitive to fashion than practical group preferred high heel shoes, which could express their own personality, it would be great to have various designs by reflecting the trendy materials and details focusing on pumps, strap and walker boots which can express individuality and supplement the body shape and height as matching to the trendy clothes. Second, as women in 20s have tendency to show more preference of a certain trendy shoes shape than women in 40s, the shoes designs for 20s should focus on certain types of shoes preferred by them by varying materials and details, rather than having various designs. However, it would be great to show various designs for the shoes for 40s. Most of the 20s are the individual and complex fashion-seeking types while the 40s have the most of practical fashion-seeking type and the least of individual fashion-seeking type.

• Journal of the Ergonomics Society of Korea
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• v.34 no.4
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• pp.303-312
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• 2015

Objective: The aim of this study is to investigate the effect of insole height change in the lumbosacral angle and physical functions in healthy males. Background: In order to release male's dissatisfaction with his height and to increase satisfaction with his body, using insole is generalized. There have been researches on female's body change in accordance with function of insole and heel height, whereas there are few researches on males. Method: Participants were divided into three groups. A control group had 10 participants who wore 0cm insole. Experimental group I had 10 participants who wore 2cm insole. Experimental group II had 10 participants who wore 4cm insole. All participants wore insoles during their daily lives for a trial period of 8 weeks. The results were evaluated before and after comparison, and we measured lumbosacral angle, balance (dynamic balance, agility, quickness) and lumbar pain (LBP). Results: This study showed that insole height affected lumbosacral angle and dynamic balance and pain. In particular, there were significant differences in the 4cm group among the three groups (p<.05). The 2cm group did show a significant difference in lumbosacral angle and pain (p<.05). Furthermore, no significant difference was observed within the control group. Conclusion: The 4cm insole height suggests that the increase of lumbosacral angle contributes to some changes in LBP, balance, pain and physical functions, probably leading to negative effects on variety of activities of daily life. Application: The results of wearing insoles with proper height will help to prevent musculoskeletal disorders.

• Physical Therapy Korea
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• v.14 no.4
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• pp.44-49
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• 2007

The purpose of this study was to investigate the effects of auditory cues in the form of a metronome on gait initiation (GI) in Parkinson's disease (PD). 2 patients (mean age: 54 yrs) with idiopathic PD participated in the study. All patients (Hoehn and Yahr disability score of 2.0) were tested in the "on" state approximately 1.5 hours following the administration and fully responding to their PD medications. Subjects first initiated walking at self-initiated speeds to determine their cadences. Then, subjects were asked to initiate gait along the walkway while keeping pace with a metronome. The metronome rate (in beats/min) was set at a cadence 85% (slow condition), 100% (normal condition) and 115% (fast condition) of gait for each subject. Subjects were able to increase the speed of GI with faster cadence, but the speed of GI for the slow condition was similar to that of the normal condition. Swing toe-off was 578.3 ms for the fast condition, 709.4 ms for the normal condition and 736.2 ms for the slow condition. Respective times for swing heel-strike were 894.3 ms, 1110.2 ms and 1119.1 ms, and stance toe-off were 1105.4 ms, 1338.5 ms, and 1343.1 ms. Except for stance unloading ground reaction forces were greatest for the fast condition and smallest for the slow condition. It appears that PD patients were able to modulate GRFs and temporal events in response to auditory cues to achieve the peak acceleration force of the swing and stance limb. The findings from this study provided preliminary data, which could be used to investigate how PD patients modulate GRFs and temporal events during GI in response to tasks.

• Physical Therapy Korea
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• v.27 no.4
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• pp.227-232
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• 2020

Background: Hallux valgus (HV) is a foot deformity developed by mediolateral deviation of the first metatarsophalangeal joint. Although various foot-toe orthoses were used to correct the HV angle, verification of the effects of kinetics variables such as ground reaction force (GRF) through three-dimensional (3D) gait analysis according to the various type of orthoses for HV is insufficient. Objects: This study aimed to investigate the effect of soft and hard types of foot and toe orthoses to correct HV deformity on the GRF in individuals with HV using 3D motion analysis system during walking. Methods: Twenty-six subjects participated in the experiment. Participants had HV angle of more than 15° in both feet. Two force platforms were used to obtain 3D GRF data for both feet and a 3D motion capture system with six infrared cameras was used to measure exact stance phase point such as heel strike or toe off period. Total walk trials of each participant were 8 to 10, the walkway length was 6 m. Two-way repeated measures ANOVA was used to determine the effects of each orthosis condition on the various GRF values. Results: The late anteroposterior maximal force and a first vertical peak force of the GRF showed that the hard type orthosis condition significantly increased GRF compared to the other orthosis conditions (p < 0.05). Conclusion: There were significant effects in GRF values when wearing the hard type foot orthosis. However, the hard type foot orthosis was uncomfortable to wear during walking. Therefore, it is necessary to develop a new foot-toe orthosis that can compensate for these disadvantages.

• The Journal of Korean Physical Therapy
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• v.25 no.2
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• pp.88-95
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• 2013

Purpose: The purpose of this study was to conduct an analysis of kinematics of lower extremities and trunk in stance phase of walking according to turning direction. Methods: Ten university students (five male, five female) who were in their 20s (mean age was 20.6 years old) participated in this study. Participants did not have participants did not have any problem with skeletal muscular system. We used the "Qualisys motion capture system" for analysis of trunk and lower extremity movement in stance phase of walking according to turning direction. We collected data while subjects walked a distance of 10 m, and at the 6 m line, subjects were required to turn to the left side and the right leg was positioned in stance phase and the left leg was positioned in swing. For data analysis, the SPSS for Windows ver. 20.0 statistics program was used in performance of one way analysis of variance according to turning direction. Results: Significant difference of trunk and lower extremities was observed for turning direction according to walking cycle (p<0.05). Upper trunk movement showed a greater increase at three dimensions than lower trunk, and in heel off phase, pelvic movement showed a greater increase than lower trunk (p<0.05). In 45 degree and 90 degrees of turning direction, all movements of trunk and lower extremities were significantly different among three events of stance phase (p<0.05). Conclusion: We suggest that three-dimensional movement analysis of trunk and lower extremities during turning movement was very important in order to indicate increasing balance or walking ability for people with impaired movement or walking.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.5
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• pp.487-495
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• 2016

In the offshore project such as semi-submersible FPU and FPSO, the free fall type life boat called TEMPSC (Totally Enclosed Motor Propelled Survival Craft) has been installed for the use of an emergency evacuation of POB (People on Board) from the topside platform. For the design of life boat arrangement for semi-submersible FPU in the initial design stage, the drop height and launch angle are required fulfill with the limitation of classification society rule and Company requirement, including type of approval as applicable when intact and damage condition of the platform. In this paper, we have been performed the numerical studies to find proper arrangement for the life boats consider drop height in various environmental conditions such as wave, wind and current. In the calculations, the contributions from static and low frequency (LF) motions are considered from the hydrodynamic and mooring analysis as well as damage angle from the intact and damage stability analysis. Also, Air-gap calculation at the life boat positions has been carried out to check the effect on the life boat arrangement. The air-gap assessment is based on the extreme air-gap method includes the effect of 1st order wave frequency (WF) motions, 2nd order low frequency roll/pitch motion, static trim/heel and set down.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.5
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• pp.35-45
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• 2001

Recently, the floor systems those require large open space may have low inherent damping due to the decline of the use of curtain walls. Furthermore, the use of the high strength materials has resulted in more flexible and longer spanning in floor systems. The long span structures such as shopping malls, offices and large assembly rooms may lead to significant dynamic response due to human activities. Excessive vibrations make the occupants uncomfortable and deteriorate the serviceability of buildings. It is now proved that footfall loading is the major source of floor vibrations. The common method of application of walking loads for the vibration analysis of structures subjected to walking loads is to inflict measured walking loads and periodic function at a node. But this method could not account for the moving effect of walking. In this study, natural frequency and damping ratio of example structure are evaluated by heel drop tests. And the application of equivalent walking loads is used for on efficient vibration analysis of the plate structures subjected to walking loads.