• Korean Journal of Applied Biomechanics
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• v.27 no.3
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• pp.219-227
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• 2017

Objective: The aim of this study was to analyze the effects of bobsleigh shoes on the lower extremity range of motion and start speed lap time and to develop bobsleigh shoes suitable for winter environments and Korean players based on sports science and optimized biomechanical performance. Background: The bobsleigh shoes used in the start section of the sport are one of the most important equipment for improving athletes' performances. Despite the importance of the start section, there are no shoes that are specifically designed for Korean bobsleigh athletes. Thus, Korean athletes have to wear sprint spike shoes instead of bobsleigh shoes to practice the start. Method: The subjects included four bobsleigh athletes from the Gangwon Province Bobsleigh Skeleton Federation. The study selected the bobsleigh shoe type A (company A) and type B (company B). We analyzed the lower extremity range of motion and sprint time (start line to 10 m) using a Motion Analysis System (USA). Results: In the measurement of the time required for the bobsleigh start section (10 m), the type A shoes demonstrated the fastest section record by $2.765{\pm}0.086sec$ and yielded more efficient movements, hip and knee flexion, hip extension, ankle dorsiflexion, plantar flexion, and inversion than the type B shoes. Conclusion: Type A shoes can yield a better performance via effective lower extremity movements in the bobsleigh start section. Application: In the future, functional analysis should be conducted by comparing the upper material properties, comfort, and muscle fatigue of bobsleigh shoes based on the Type A shoes to develop such shoes suitable for Koreans.

• Korean Journal of Applied Biomechanics
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• v.21 no.4
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• pp.397-403
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• 2011

The purpose of this study is to analyze the immediate effects of five toed shoes on foot structure. Subjects consisted of 26 college-aged women with pes planus. X-ray analysis of student feet were performed both barefooted and with five toed shoes. Dependent variables were hallux valgus angle, calcaneal inclination angle, 1st metatarsal declination angle, and intermetartarsal angle. Independent t-test was used for statistical analysis along with SAS. Overall, there were statistically significant changes of test subject's dependent variables when wearing five toed shoes. Specifically, the hallux valgus angle decreased, the calcaneal inclination angle and 1st metatarsal inclination angle increased, and intermetatasal angles both increased and decreased, shifting towards normal range. In every case the dependent variables shifted towards a more normal range while subjects wore five toed shoes. This study only examined the immediate corrective effects of five toed shoes on foot structure, but long-term studies are needed to understand the prolonged effects of five toed shoes on foot structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1228-1231
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• 2004

We analyzed the impulse on 24 sensors location under the foot using the Parotec system for the investigation of the relationship between the shoe type and the foot pathologies. Total 7 kinds of shoes, i.e. sport shoe, high heel shoes (5cm heel, 8cm heel, 13cm heel), platform shoe, inline skate, and heelys were evaluated for 20 normal subjects. Compared with the impulse distribution of the sport shoe, greater impulses were shown at the 1$^{st}$ phalange and the 1$^{st}$ metatarsal-phalangeal head in high-heel shoes, lateral tarsal bone and medial metatarsal bone in platform shoe, medial tarsal bone in inline-skate, and medial tarsal bone and 1st phalange in heelys shoe. The result of this study is expected to provide useful information about the relationship between the shoe type and the foot pathologies.ies.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.395-409
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• 2017

Objective: The purpose of this study was to optimize the number and positions of foot pressure sensors using the reliability analysis of the center of pressure (COP) in smart shoes. Background: Foot pressure can be different according to foot region, and it is important which region of the foot pressure needs to be measured. Method: Thirty adults (age: $20.5{\pm}1.8years$, body weight: $71.4{\pm}6.5kg$, height: $1.76{\pm}0.04m$) participated in this study. The foot pressure data were collected using the insole of Pedar-X system (Novel GmbH, USA) with a sampling frequency of 100Hz during 1.3m/s speed walking on the treadmill (Instrumented treadmill, Bertec, USA). The intraclass correlation coefficients (ICC) were calculated between the COP positions using 4, 5, 6, 7, 8, and 99 sensors, while one-way repeated measure ANOVA was performed between the standard deviation (SD) of the COP positions. Results: The medio-lateral (M/L) COP position using 99 sensors was positively correlated with the M/L COP positions using 6, 7, and 8 sensors; however, it was not correlated with the M/L COP positions using 4 and 5 sensors during landing phase (1~4%) (p<.05). The antero-posterior (A/P) COP position using 99 sensors was positively correlated with the A/P COP positions using 4, 5, 6, 7, and 8 sensors (p<.05). The SD of the COP position using 99 sensors was smaller than the SD of the M/L COP positions using 4, 5, 6, 7, and 8 sensors (p<.05). Conclusion: Based on our findings, it is desirable to arrange at least 6 sensors in smart shoes. Application: The study of optimizing the number and positions of foot pressure sensors would contribute to developing more effective smart shoes using foot pressure technology.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.465-474
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• 2015

Objective : A study and development of Korean Bobsleigh athletes's shoe which considers their physical condition has yet to be completed. So this study examines the effects of running shoes used by athletes based on plantar pressure and sprint time in order to provide raw data for the development of bobsleigh shoes suitable for Koreans. Method : The study selected seven bobsleigh athletes as subjects and selected three pairs of spiked running shoes from three companies, which will be referred to as Company N (Type A), Company A (Type B), and Company M (Type C). To analyze sprint time and plantar pressure for each shoe, the subject of the study were instructed to wear the selected shoes and to drag a sled at maximum sprint for 15 meters for 15 meters for in each condition that would be in real bobsleigh competitions. Results : The average sprint intervals for each athlete in each pair of shoes revealed Type C produce the fastest sprint in the order of Type C < Type A< Type B. Shoe Type C also had the largest contact area in order of Type C > Type B > Type A (p<.01). None of the three shoe types seem to yield a distinct advantage in terms of maximum average pressure or maximum pressure. Conclusion : In the future, functional analysis should be carried out by comparing the material properties, hardness, and toe spring of shoes based on the Type C shoe from Company M in order to develop bobsleigh shoes suitable for Koreans.

• Korean Journal of Applied Biomechanics
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• v.21 no.1
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• pp.9-16
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• 2011

The purpose of this study is to analyze the effects of both various shoe types and bare feet on ground reaction force while walking. Ten first-year female university students were selected. A force platform(Kistler, Germany) was used to measure ground reaction force. Six types of shoe were tested: flip flops, canvas shoes, running shoes, elevated forefoot walking shoes, elevated midfoot walking shoes, and five-toed shoes. The control group was barefooted. Only vertical passive/active ground reaction force variables were analyzed. The statistical analysis was carried out using the SAS 9.1.2 package, specifically ANOVA, and Tukey for the post hoc. The five-toed shoe had the highest maximum passive force value; while the running shoe had the lowest. The first active loading rate for running shoes was the highest; meanwhile, bare feet, the five-toed shoe, and the elevated fore foot walking shoe was the lowest. Although barefoot movement or movement in five toed shoes increases impact, it also allows for full movement of the foot. This in turn allows the foot arch to work properly, fully flexing along three arches(transverse, lateral, medial), facilitating braking force and initiating forward movement as the tendons, ligaments, and muscles of the arch flex back into shape. In contrast movement in padded shoes have a tendency to pound their feet into the ground. This pounding action can result in greater foot instability, which would account for the higher loading rates for the first active peak for padded shoes.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.219-223
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• 2013

The purpose of the study was to investigate the effects of gymnasts shoes on risk factors of anterior cruciate ligament injuries during drop-landing followed by vertical jump in female gymnasts. Thirteen female gymnasts were recruited and performed randomly drop-landing followed by vertical jump in height of her knee with and without shoes. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. Data were analyzed with paired samples t-test with Bonferroni correction. Female gymnasts with shoes showed more reduced thigh maximum adduction angle, and knee maximum extension moment than without shoes. Female gymnasts with shoes showed more increased shank maximum abduction angle than without shoes. In conclusion, Female gymnasts with shoes reduced anterior cruciate ligament injuries risk factors.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.235-243
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• 2008

The purpose of this study is to find out the effect of Growth Hormone promotin and kinetic factors on Growth Hormone Activated Shoes. The results of the present study were as follows; First, there was a significient difference between a normal shoes and the Growth Hormone activated shoes in the student's GH secretion with running test, and there was a significant interaction effect between shoes and distance. therefore it can be assumed that there is a significant effect of GH secretion in student at growth period during running with Growth Hormine Activated Shoes. Second, Within 4km walking, Growth Hormone secretion was in creased averagely in student. Third, Growth Hormone Activated Shoes make a large load for light motion as walking. For heavy motion as running, it make a large impulsion but good pressure distribution and small loading rate.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.231-241
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• 2011

The purpose of this study was to analyze the distribution of foot pressure generated by active materials of a functional insole. Comfort is an important consideration while selectingfootwear and insoles. Consequently, it has an influence on injury. The development of new materials for functional insoles is considered one of the more important points for their manufacture. The method adopted in this study is as follows. First, ten healthy males were selected as subjects for the study. Each subject's foof was pre-screened podoscope(Alfoots, Korea) to check for the presence of any foot abnormalities, Two kinds of equipment were used for the study: a foot pressure device from Pedar-X, Germany, and a treadmill from Pulsefitness, UK. Next, each subject was asked to test four types of insoles(insoles of outdoor shoes, indoor shoes, walking shoes, and sports shoes) via walking trials on the treadmill at a constant speed of 4.2 km/h. The pressure distribution data(contact area, maximum force, maximum peak pressure, and maximum mean pressure) was collected using the pressure device at a sampling rate of 100 Hz. Results of the tests showed that all four types of functional insoles increased contact areas whit the foot. Further, functional insoles of walking shoes and sport shoes decreased the foot pressure. From these results, we conclude that the active materials of functional insoles of shoes can increase the contact area and provide greater comfort.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.174-181
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• 2005

We analyzed the pressure, impulse on 24 sensors location under the foot using the Parolee system. Total 7 kinds of shoes, i.e. sport shoe, high heel shoes (5cm heel, 8cm heel, 13cm heel), platform shoe, inline skate, and heelys were evaluated for 20 normal subjects. Compared with those of sport shoe, greater pressure and impulse were shown on the 1 st phalange and the 1 st metatarsal head and greater impulse on the medial tarsal bone in high-heel shoes. Greater pressure and impulse were shown on medial metatarsal bone and the lateral tarsal bone in platform shoe. Greater impulse was shown on the medial tarsal bone in inline-skate. Heelys shoe showed smaller impulse on the central area of foot. The result of this study is expected to provide useful information about the relationship between the shoe type and the foot pathologies.