• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.1-9
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• 2008

The purpose of this study was to investigate the effect of different obstacle heights on the plantar foot pressure during obstacle crossing. Sixteen healthy adults who had no musculoskeletal disorders were instructed to perform unobstructed level walking and to step over obstacles corto 10cm, 20cm, 30cm. Plantar foot forces and pressures were recorded by the Footmat system(Tekscan, Boston, USA) during level and obstacle walking with barefoot. Plantar foot surface was defined as seven regions for pressure measurement; two toe regions, three forefoot regions, one midfoot region, one heel region. One-way ANOVA was used to compare each region data of foot according to various heights. The results indicated that there are significant differences on peak pressure and maximal forces regarding each region at stance phase. As height of obstacle became high, the pathway of COP had a tendency to be short and abducted. Plantar pressure of foot could be changed by obstacle height and these findings demonstrated that obstacle with different height have an effect on structure and function of the foot.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.19-26
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• 2014

This study investigated foot pressure patterns between experienced skiers and intermediate skiers during alpine skiing. Five experienced skiers and five intermediate skiers participated in this study. Foot pressure measurement system was used to measure vertical ground reaction force (vGRF) and contact area under the six plantar regions. Each participant was asked to perform basic parallel turns and carved turns on a $18^{\circ}$ groomed slope. Each right turn was divided into the initiation phase, the steering phase 1 and 2. For the initiation phase of the basic parallel turns, significantly greater contact area was found on the LRF and RRF of the intermediate skiers (p<.05) and significantly greater vGRF was found on the LRF of the intermediate skiers (p<.05). Also significantly greater vGRF and contact area were found on the LRF and RRF of the intermediate skiers at the steering phase 1 (p<.05) and on the LRF of the intermediate skiers at the steering phase 2 (p<.05). For the carved turns, significantly greater vGRF and contact area were found on the LRF and RRF of the intermediate skiers at all three phase (p<.05). On the other hand, significantly greater vGRF was found on the RFF of the experienced skiers at the steering phase 1 (p<.05). Also significantly greater vGRF and contact area were found on the RMF of the experienced skiers at the steering phase 2 (p<.05). In order to increase performance, we suggest that the intermediate skiers should be unweighted at the initiation phase and shift the body weight to the forefoot of the outer foot at the steering phase 1. Also, the outer ski should be loaded more than the both skis at the steering phase 1 and 2.

• Journal of Convergence for Information Technology
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• v.9 no.8
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• pp.140-147
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• 2019

The purpose of this study is to find biomechanical parameters for optimal shoes production through an ergonomic usability assessment of five existing types of shoes preferred by B-BOY. Ten experts and ten non-experts participated in the experiment, and 12 infrared cameras (Qualis, Oqus), force plate (Kistler, 9286AA) and foot pressure plate (Zebris Gmbh, Zebris PDM-System) were used to obtain the data. The results of the study are as follows. First, P shoes with a friction coefficient of 0.38 and a free moment of 0.32 N/m/kg are desirable in terms of traction capability and safety. Second, on the cushion, it was found that the N shoes 2.51 N, sec/kg and non-expert, and 2.86 N and sec/kg were suitable. Third, it is deemed appropriate for C shoes with a forefoot average pressure of 10.11 KPa (right), 10.05 KPa (left), and V shoes with a rearfoot average pressure of 8.4 KPa (right) and 8.36 KPa (left). In conclusion, the combination of the structure and material of V shoes should be developed for traction and stability, N shoes for cushion, and walking balance for C and V shoes.

• Journal of Korean Foot and Ankle Society
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• v.28 no.1
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• pp.21-26
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• 2024

Purpose: Foot pressure measurement devices are used widely in clinical settings for plantar pressure assessments. Despite the availability of various devices, studies evaluating the inter-device reliability are limited. This study compared plantar pressure measurements obtained from HR Mat (Tekscan Inc.) and EMED-n50 (Novel GmbH). Materials and Methods: The study involved 38 healthy male volunteers. The participants were categorized into two groups based on the Meary's angle in standing foot lateral radiographs: those with normal feet (angles ranging from -4° to 4°) and those with mild flatfeet (angles from -8° to -15°). The static and dynamic plantar pressures of the participants were measured using HR Mat and EMED-n50. The reliability of the contact area and mean force was assessed using the interclass correlation coefficient (ICC). Furthermore, the differences in measurements between the two devices were examined, considering the presence of mild flatfoot. Results: The ICC values for the contact area and mean force ranged from 0.703 to 0.947, indicating good-to-excellent reliability across all areas. EMED-n50 tended to record higher contact areas than HR Mat. The mean force was significantly higher in the forefoot region when measured with EMED-n50, whereas, in the hindfoot region, this difference was observed only during static measurements with HR Mat. Participants with mild flatfeet exhibited significantly higher contact areas in the midfoot region for both devices, with no consistent differences in the other parameters. Conclusion: The contact area and mean force measurements of the HR Mat and EMED-n50 showed high reliability. On the other hand, EMED-n50 tended to record higher contact areas than HR Mat. In cases of mild flatfoot, an increase in contact area within the midfoot region was observed, but no consistent impact on the differences between the two devices was evident.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.41-55
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• 2005

In this study, weight carrying pattern analysis and comparison method of four foot region were suggested. We used three types of club(driver, iron7, pitching wedge). This analysis method can compare between top class golfer and beginner. And the comparison data can be used to correct the swing pose of trainee. If motion analysis system, which can measure the swing speed and instantaneous acceleration at the point of hitting a ball, is combined with this plantar foot force analysis method, new design development of golf shoes to increase comfort and ball flight distance will be available. 1. Regional change of force acting, in address, is evenly distributed on both feet. In back swing top, 76% on right foot, 75% on left foot as impact, and 86% on left foot as finish. As regional force acting, in address, pros get high marks on rare and inside of right foot and rare and outside for amateurs. In back swing top, it is higher as fore and inside of left foot, pros as rare part of right foot and amateurs as forefoot. In impact, it is higher for pros and amateurs in outside and rare part of left foot and fore and inside of right foot. In finish, for both pros and amateurs, it is higher for outside and rare parts of left foot. 2. For each club, forces are evenly distributed on both feet in address. In back swing top, the shorter a club is, the higher impact on right foot and the higher finish distribution on left foot. For all the clubs used, in each region, pros get higher on rare and inside of right foot and as amateurs on rare and outside of left foot in address. In back swing top, for all clubs, pros get higher on rare and outside of right foot as fore and outside for amateurs. In impact acting, for all clubs, rare and outside of left foot get higher. In finish, force concentrates on rarefoot. 3. On both feet force, right foot forces of amateurs is higher than those of pros in back swing top. In impact and finish, pros get higher on left foot.

• Physical Therapy Korea
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• v.24 no.1
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• pp.1-8
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• 2017

Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group ($n_2=15$). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1242-1246
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• 2016

Heel rocking phase in gait cycle is from initial contact to forefoot contact. The purpose of this study was to investigate the effect of age on heel rocking time. Seven young women ($21.9{\pm}1.5yrs$) and seven elderly women ($74.1{\pm}6.7yrs$) participated in this study. Subjects wore the shoes equipped with pressure sensors and walked along 10 m walkway at comfortable speeds. Stride time, stance time, and heel rocking time were compared between groups. Stride time was not different between groups (p=0.087). Stance time was longer (p<0.001) but heel rocking time was shorter in the elderly than in the young (p<0.001). The shorter heel-rocking time in elderly women indicates less efficient shock-absorption in the heel-rocking phase, which might be related to the abnormal control and/or reduced performance of ankle dorsiflexors.

• PNF and Movement
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• v.21 no.1
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• pp.27-35
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• 2023

Purpose: Hallux valgus (HV) is one of the most common chronic foot disorders, occurring when the first toe deviates laterally toward the other toe. HV impairs muscle strength and affects gait function (postural sway and gait speed). Thus, this study aims to investigate using the FDM system the effect of wearing braces on gait while wearing a virtual reality (VR) device. Methods: This study was conducted on 28 healthy adults with HV of 15 degrees or more. To compare differences in walking, depending on whether a toe brace can be worn, the subject walked without wearing anything, walked after wearing the VR device, and walked after wearing the VR device and the toe brace, and the FDM system was used for the gait ability measurement analysis. Results: As a result of a one-way repeated analysis of variance, the walking speed-related variables (cadence, velocity, etc.) in the HV group were higher during comfortable walking. In addition, walking while wearing a VR device and walking while wearing a VR device and a toe brace demonstrated more significant values in terms of six gait parameters (double stance phase, loading response, stage, stage, stage, and stage). The maximum pressure of the forefoot was significantly reduced when walking while wearing a VR device and a toe brace compared to comfortable walking, but in all variables, there was no statistically significant difference between walking while wearing a VR device and walking while wearing a VR device and a toe brace. Conclusion: Orthosis with a VR device during gait (OVG) and gait with a VR device (GVR) affect gait in HV patients. However, there was no significant difference between GVR and OVG. Thus, it is necessary to conduct experiments on various HV angles and increase the duration of wearing the toe brace.

• Journal of Hospice and Palliative Care
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• v.12 no.3
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• pp.139-146
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• 2009

This study was designed to examine the effect of aroma massage therapy on lower extremity edema of terminal cancer patients. Methods: A total of thirty-six terminal cancer patients with lower extremity edema were divided into two groups: the aroma massage group received massage with blending oil which was applied from toes to 10 cm above the knee of the subject for 15 to 20 minutes in each turn, while the control group received sham aroma massage (applied with carrier oil only). The circumferences of the fore-foot, ankle and calf were measured before massage and 30 minutes, 2 hours, and 12 hours after massage. The blood pressure, pulse and body temperature were also measured to find the change of subject's physiologic conditions. Results: There were no significant differences in blood pressure, heart rate, body temperature and lower extremity circumferences between two groups. However, edema at each site was slightly improved in the treatment group after the aroma massage therapy, compared to baseline data (P<0.05). In addition, the reduction of lower extremity circumference was maximal at 2 hours in foot, 30 min in right ankle and 12 hours in right calf after aroma massage therapy (P<0.05). Conclusion: Our results suggest that aroma massage therapy is not effective on the lower extremity edema of terminal cancer patients.