• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.9 s.240
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• pp.1191-1198
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• 2005

This paper is concerned with the numerical investigation of the landing impact characteristics of sport shoes to the landing mode. In most court sport activities, jumping and landing are fundamental motions, and the landing motion is largely composed of forefoot and rearfoot landing modes. Since the landing impact may, but frequently, lead to unexpected injuries of players, the investigation of its characteristics and the sport shoes design for reducing it are of a great importance. To investigate the landing impact characteristics to the landing mode, we construct a shoes-leg coupled model and carry out the numerical simulation by an explicit finite element method.

• Journal of Korean Foot and Ankle Society
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• v.15 no.2
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• pp.58-61
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• 2011

Morton's neuroma is a common cause of forefoot pain, and is also known to be a entrapment neuropathy rather than a true tumor. Precise physical examination is necessary to differentiate from other diagnoses of similar symptoms. If proper conservative treatment modalities fail for this neuritis, neurectomy of interdigital nerve is generally performed, with the results of up to 80% of patient's satisfaction. However the failure rate of 2% to 35% should be improved by proper diagnosis and careful surgery.

• The Journal of Korean Physical Therapy
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• v.22 no.1
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• pp.47-51
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• 2010

Purpose: The purpose of this study was to determine whether there are any differences, with and without a toe spreader (TS), in dynamic foot pressure distribution in children with spastic diplegic cerebral palsy. Methods: Dynamic foot pressure recording using the RSscan system were obtained during walking in 12 participants (male=7, female=5) with and without TS. Mean force was measured for four different plantar regions; great toe, forefoot, midfoot, hindfoot. Displacement of center of pressure (COP), velocity of COP displacement and stance time were also measured during gait. Results: TS walking exhibited statistically significant decrease of mean force under great toe and forefoot (p<0.05), compared with a barefoot walking. Also, TS walking exhibited statistically significant increase of antero-posterior displacement of COP (p>0.05). Conclusion: These findings indicate the potential clinical utility of toe spreader to correct dynamic foot pressure during stance phase in children with spastic diplegic cerebral palsy.

• 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.27 no.3
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• pp.229-238
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• 2017

Objective: The purpose of this study was to identify the effects of taping therapy and inner arch support on pes planus lower extremity alignment and gait. Method: The study was conducted on 13 women in their 20s who had pes planus and no gait problems. Independent variables were the condition of wearing basic socks (S1) and the condition of wearing socks with taping therapy and inner arch support (S2). The dependent variables were resting calcaneal stance position (RCSP), plantar pressure distribution during gait, and underlying and medial longitudinal arch angle measured using radiography. Statistical analysis was performed using the Wilcoxon test with SPSS 23.0 for comparison of S1 and S2. Results: In the RCSP measurement, the angle range of S2 changed to normal. Meary's angle appeared to be less than the angle of S1, indicating alleviation of the degree of pes planus. The calcaneal pitch angle increased at S2 from that at S1. The plantar pressure distribution was divided into four areas (toe, forefoot, midfoot, and hindfoot). At S2, the maximum pressure increased in the toe and midfoot. The maximum force increased significantly in the toe and midfoot but decreased significantly in the forefoot and hindfoot. In addition, the contact area increased overall especially at the midfoot and hindfoot. Contact time decreased in the toe and forefoot, but increased in the midfoot and hindfoot. Conclusion: Taping therapy and inner arch support showed structural improvement of the pes planus. In addition, the force and pressure applied to the foot during walking are distributed evenly in the area of the sole, thus positively affecting walking.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.2
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• pp.63-72
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• 2015

Purpose: The purpose of this study was to investigate the foot pressure of subjects with hallux valgus following conservative management. Methods: The subjects (20 females) were divided into 2 groups; Hallux valgus group (10) and Control group (10) who could evaluate questionnaire & weight bearing X-ray. All the participants were evaluated distribution of foot pressure by Zebris FDM-S system with conservative management (taping therapy and hallux valgus device) during single-limb stance. Results: The Hallux valgus group (HVG) was significantly different than Control group (CG) in hallux valgus angle(p<0.05). The Hallux valgus group with Foot Device (HVG-FD), Hallux valgus group with Taping (HVG-Tp) and Hallux valgus group with Foot device and Taping (HVG-FD&Tp) was not significantly different than CG in hallux valgus angle (p<0.05). The HVG was not significantly different than CG in forefoot (p1, p2, p3), significantly different than CG in rearfoot (p7) about foot pressure during single-limb stance (p<0.05). The HVG-FO and HVG-FO and TP was significantly different than HVG in forefoot (p1, p2, p3), on significantly different than HVG in rearfoot (p7) about foot pressure during single-limb stance (p<0.05). There was significantly correlation HVG-FO and HVG-FO & TP in forefoot (p1, p2, p3) was negative correlation (p<0.05) and in rearfoot (p7) was positive correlation (p<0.05). Conclusion: This study showed that hallux valgus were effected hallux valgus angle and foot pressure by various treatment methods during single-limb stance. Further study is needed to measure various age and work with hallux valgus for clinical application.

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.74-80
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• 2005

Purpose: A retrospective review of the radiographs of the proximal metatarsal osteotomy and distal soft tissue procedure for hallux valgus, evaluating the correction of the tibial sesamoid, was undertaken. We evaluated the correlation between the reduction of the tibial sesamoid and the clinical outcomes. Materials and Methods: 17 patients (23 cases) with moderate to severe hallux valgus deformity underwent the proximal metatarsal osteotomy and distal soft tissue procedure. The preoperative and last follow-up radiographs were reviewed according to the tibial sesamoid grade classification recommended by the Research Committee of the American Orthopedic Foot and Ankle Society (AOFAS). We divided them into two groups according to the reduction of the tibial sesamoid. We anaylyzed the clinical outcomes in each group according to Mayo Clinic Forefoot Scoring System (FFSS). Results: In all of the patients, the preoperative tibial sesamoid position were grade 2 or greater. At the last follow-up, 52% (n=12) were grade 1 or less (Group I) and 48% (n=11) were grade 2 or greater (Group II). In group I, the forefoot score was improved from preoperative mean value of 32.0 points to final follow-up value of 66.3 points. In group II, the forefoot score was improved from preoperative mean value of 31.7 points to final follow-up value of 65.9 points. There was no statistical significance between postoperative, average scores in group I and II (p>0.05). Conclusion: The position of the tibial sesamoid was corrected insufficiently in almost half of all cases. In view of clinical outcomes, there was no significant difference between the corrected group and the other group.

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.1-8
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• 2005

Purpose: We compared the bony arrangements of the forefoot in 2 different years, 1982 and 2004, to determine any changes with time period of 22 years. Materials and Methods: The radiographs of 200 normal Korean adults, 100 male and 100 female volunteers, were evaluated both in 1982 and 2004. The radiographic results were evaluated with as follows; hallux valgus angle (HVA), intermetatarsal angle (IMA), morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges. The mean ages were 38 years (23-52years) in 1982, and 37 years (24-50years) in 2004. Results: The mean of HVA decreased from 15.6 degrees in 1982 to 14.3 degrees in 2004 (p=0.047), and the mean of IMA increased from 8.0 degrees in 1982 to 9.4 degrees in 2004 (p=0.031). The morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges were not different between the two study years. Conclusion: Comparing with those of 1982 measurements, we found an increase of IMA and a decrease of HVA. A prospective study may be needed to illuminate course of the changes.

• Korean Journal of Applied Biomechanics
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• v.27 no.4
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• pp.239-245
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• 2017

Objective: The bobsleigh shoes used in the start section are one of the most important equipment for improving the competition. Despite the importance of the start section, there are no shoes that are specific for bobsleigh athletes in Korea and Korean athletes have to wear sprint spike shoes and practice the start instead of wearing bobsleigh shoes. The objective of the present study was to provide data for improving the performance of Korean bobsleigh athletes by investigating the differences in their split time, plantar pressure, and forefoot bending angle based on skill levels at the start of a run under the same conditions as training conditions. Method: Six Korean bobsleigh athletes were divided into two groups, superior (n=3) and non-superior (n=3). A digital speedometer measured the split time at the start; the Pedar-X system (Novel, Germany) measured plantar pressure. Plantar pressures and split times were measured as the athletes pushed a bobsleigh and sprinted at full speed from the start line to the 10-m mark on the bobsleigh track. An ultra-high-speed camera was used to measure the forefoot bending angle during the start phase. Results: Significant between-group differences were found in split times (p<.000; superior = 2.38 s, non-superior = 2.52 s). The superior group had a larger rearfoot (p<.05) contact area, maximum rearfoot force (p<.01), and a larger change in angles 3 and 4 (p<.05). Conclusion: At the start of a bobsleigh run, proper use of the rearfoot for achieving effective driving force and increasing frictional resistance through a wider frictional force can shorten start time.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.43-53
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• 2006

Among several movements that occurred upon a slope, golf swing is the most typical one because environmental conditions dynamically vary with many kinds of slopes. Some studies on the golf swing were performed about a weight transfer on flatland, however, there couldn't be seen any study about the weight transfer on slope elsewhere. Therefore, the purpose of this study was to provide quantified data to objectively test the coaching words and keys about the weight transfer at sidehill slope during goal impact EspeciaIly sidehill Slopes with ball above the feet. Four highschool golfer, who have average handy 5, were recruited for this study. Plantar pressure distribution and cinematographic data were collected during golf swing in the conditions of flatland, $5^{\circ}$, $10^{\circ}$ and $15^{\circ}$sidehill slope simultaneously. The two data were used to synchronize the two data later. The plantar regions under the foot were divided into 8 regions according to the directly applied pressure pattern of the subject to insole sensor. The 8 foot regions were hullux, medial forefoot, central forefoot, lateral forefoot, medial midfoot, lateral midfoot, medial heel, and lateral heel. And the plantar pressure data was also divided into four movement address, phases-backswing. downswing, and follow-through phases according to the percentage shown to the visual information of film data. Based on the investigations on public golf books and experiences of golfers, it was hypothesized by the authors in the early of this study that the steeper slopes are, the more weight loads on left foot that positions at the higher place. When observing the results of plantar pressure and vertical force curves according to the sidehill slope conditions, the hypothesis could be accepted.