• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.186-199
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• 2016

The shoe last which is the framework for the shoemaking is intensively combined with the 3D data and technologies. International shoe companies have already commercialized 3D printing technology in producing the shoe, but domestic shoe companies are still in their early stages. This study used the 3D scanning, 3D modeling and 3D printing of the high-technology to make the shoe last. This 3D producing processes should be helpful in building competitiveness in domestic shoe industry. The 3D foot scanning data of men in 30s(n=200) were collected in SizeKorea(2010). The basic statistics, factor and cluster analysis were performed. They were categorized in 3 groups by 3D foot measurement data, and the standard models were selected in each group. The cross sections in XY, YZ and XZ planes sliced from 3D scan data of the standard model were used in the sketches of the 3D shoe last modeling. The 3D shoe last was modeled by Solidworks CAD and printed by MakerBot Replicator2; a desktop 3D printer. This research showed the potential for utilization of 3D printing technology in the domestic shoe industry. The 3D producing process; 3D scanning, 3D modeling and 3D printing is expected to utilized widely in the fashion industry within the nearest future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.541-545
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• 2014

In this paper, the angle of the thighs that appear during walking condition to balance estimation to the left and right leg was occurred during normal walking. Get over to the limitations of gait analysis using image processing or foot pressure that was used a lot in the previous, the angle of the thigh were used for estimation of asymmetric gait. We implemented heathy five adult male to test targeting and gait and obtained cycle data from 10 times. For this research, Thigh-Angle measurement device were developed, and attached to in a position of $20^{\circ}$ for flexion and $15^{\circ}$ for extension to measure the angle of the thigh. Also, in order to verify the reliability of estimation of asymmetric gait using thigh-angle, it was compared with the result of asymmetric gait estimation using foot pressure. The results of this paper, using the thigh angle is the average of 16.84% higher than using pressure to accuracy of determine the gait imbalance.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.1
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• pp.147-162
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• 1997

When designing workplaces or arranging controls on panel, devices and controls should be placed within the reach of operator's arm or foot to guarantee effective performances. Most of the existing research on the reach volume were based on measurements of a few subject's arm reach, and limited to Caucasian and Chinese populations. Furthermore, reach volume considering foot or trunk motion have not been investigated. Range of human joint motion and that of two degrees of freedom motion are needed to generate reach volume analytically using the sweeping algorithm. However, range of two degrees of freedom motion has not been measured up to now. Therefore, range of two degrees of freedom motion was measured in this research, where 47 college students were participated voluntarily as subjects. The results showed that the motion of one joint can be limited by the motion of another motion, that is to say, the shoulder flexion was decreased significantly when the shoulder was adducted or abducted. Second, new approximate algorithms generating reach volumes were suggested, in which range of two degrees of freedom motion was used as input data. Depending upon the body segment included such as trunk, arm and leg, three types of reach volume were provided, in which the human body was modeled as a multilink system based on the robot kinematics and the sweeping method was employed. Reach volume generated analytically in this study showed statistically reasonable results when compared with that obtained from direct measurement.

• Korean Journal of Applied Biomechanics
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• v.30 no.1
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• pp.27-35
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• 2020

Objective: The purpose of this study was to investigate the influence of clubhead velocity through regression analysis on the magnitude and time difference of the forward-backward, mediolateral, and vertical ground reaction peak forces generated by force plate during golf swing. Method: 16 subjects (age: 20.5±4.2 yrs, height: 176.0±5.4 cm, weight: 77.8±5.9 kg, handy: 2.4±1.7) who is elite golf player in high school and university, participated in this study. The study method adopted three-dimensional analysis with 8 cameras and ground reaction force measurement with two force plate. The analysis variables were clubhead velocity, and ground reaction analysis variables set four events in each graph based on the peak forces commonly generated in Fx, Fy, and Fz graphs of the ground reaction data during the golf swing. Results: As a result of analyzing the influence of ground reaction magnitude difference on clubhead velocity, the influence on clubhead velocity was ym4, zm1, xm4, zm2. The larger ym4, xm4, zm1, the fasterthe clubhead velocity, but the smallerthe zm2, the faster the clubhead velocity. And in time difference, the influence on the clubhead velocity was in the order of xt4, zt1, zt3. The shorter xt4, zt1, zt3 showed faster clubhead velocity. Conclusion: The leftfoot played a leading role in increasing the velocity of the clubhead. Although the result was caused by the interaction of the right foot and the left foot during the swing, the role of the left foot is relatively large.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.935-944
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• 2014

This study was about to investigate the characteristics of elementary school students' feet growth, comparing and analyzed the measured values and the index values of 3D scan data. As the results from analyzing the measured values, the all measurement items excluding 'Toe 5 angle' showed some significant differences among the age classes, knowing that the elementary school students' feet were continually grown. Although, the items of length, thickness, width, height and circumference indicate some rapid growth of feet at 11 years old, but it appears slowing growth of 'Foot width' after the age of 11 years old. The angle item didn't show any sequential differences according to ages. As the results from analyzing the index values, the children in higher grades have longer 'Toe 5', thicker ankles, wider and thicker the superior part of feet than the children in lower grades. For the superior and the middle part of feet were lowly raised, their Arch height was low and thick. The inferior part of feet showed narrow width and higher height. Giving that the Medial ball width was wide and the Toe 1 angle is high for the children in higher grades, it is expected that the Metatarsophalangeal I might be more projected than that of children in lower grades. Likewise, knowing that the male students' feet shape was bigger than female students' feet from the result that the male students' index values were higher.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.29-35
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• 2011

The relationship between hydrologic processes and scale is one of the more complex issues in surface water hydrology. Disturbances that change vegetation and/or soil properties have been known to subsequently alter the landscape. The primary objective of this study was to estimate the grain size of soils with different properties from the hydraulic conductivity using pedotransfer functions. The double ring infiltrometer method was used to measure the vertical hydraulic conductivity of three soils under different soil planar surface treatments. Seven selected pedotransfer functions were used to estimate percentile diameters and the reduction in infiltration caused by compaction was misconstrued as caused by changes in percentile diameter. Results showed that compaction on the sandy loamy foot paths reduced the hydraulic conductivity by about 50%. The study showed that perceptual models of infiltration processes and appreciation of scale problems in modeling are far more sophisticated than normally presented in texts. Hydraulic measurement methods are still relevant and will provide significant information of grain size of the soils.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.38-46
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• 2011

3D motion analysis system which is currently widely used for walking analysis has limitations due to both necessity of wide space for many cameras for measurement, high cost, and complicated preparation procedure, which results in low accessability in use and application for clinical diagnosis. To resolve this problem, we developed 3-dimensional wireless ambulatory measurement system based on inertial sensor which can be easily applicable for clinical diagnosis for lower extremity deformity and developed system was evaluated by applying for 10 elderly people with diabetes mellitus. Developed system was composed of wireless ambulatory measurement module that consists of inertial measurement unit (IMU) which measures the gait characteristics, microcontroller which collects and precesses the inertial data, bluetooth device which transfers the measured data to PC and Window's application for storing and processing and analyzing received data. This system will utilize not only to measure lower extremity (foot) problem conveniently in clinical medicine but also to analyze 3D motion of human in other areas as sports science, rehabilitation.

• PNF and Movement
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• v.20 no.1
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• pp.59-66
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• 2022

Purpose: The aim of this research was to verify the relationship between three-dimensional (3D) ground reaction force (GRF) and severity of leg length discrepancy (LLD) while walking at a normal speed. It used a 3D motion analysis system with force platforms in standing workers with LLD. Methods: Subjects comprising 45 standing workers with LLD were selected. Two force platforms were used to acquire 3D GRF data based on a motion analysis system during gait. Vicon Nexus and Visual3D v6 Professional software were used to analyze kinetic GRF data. The subjects were asked to walk on a walkway with 40 infrared reflective markers attached to their lower extremities to collect 3D GRF data. Results: The results indicated the maximal force in the posterior and lateral direction of the long limb occurring in the early stance phase during gait had significant positive correlation with LLD severity (r = 0.664~0.738, p <0.01). In addition, the maximal force medial direction of the long limb occurring in the late stance phase showed a highly positive correlation with the LLD measurement (r = 0.527, p <0.01). Conclusion: Our results indicate that greater measured LLD severity results in more plantar pressure occurring in the foot area during heel contact to loading response of the stance phase and the stance push-off period during gait.

• Annals of Rehabilitation Medicine
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• v.42 no.6
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• pp.872-883
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• 2018

Objective To replace camera-based three-dimensional motion analyzers which are widely used to analyze body movements and gait but are also costly and require a large dedicated space, this study evaluates the validity and reliability of inertial measurement unit (IMU)-based systems by analyzing their spatio-temporal and kinematic measurement parameters. Methods The investigation was conducted in three separate hospitals with three healthy participants. IMUs were attached to the abdomen as well as the thigh, shank, and foot of both legs of each participant. Each participant then completed a 10-m gait course 10 times. During each gait cycle, the hips, knees, and ankle joints were observed from the sagittal, frontal, and transverse planes. The experiments were conducted with both a camera-based system and an IMU-based system. The measured gait analysis data were evaluated for validity and reliability using root mean square error (RMSE) and intraclass correlation coefficient (ICC) analyses. Results The differences between the RMSE values of the two systems determined through kinematic parameters ranged from a minimum of 1.83 to a maximum of 3.98 with a tolerance close to 1%. The results of this study also confirmed the reliability of the IMU-based system, and all of the variables showed a statistically high ICC. Conclusion These results confirmed that IMU-based systems can reliably replace camera-based systems for clinical body motion and gait analyses.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.142-150
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• 2015

Purpose: Restoration of ankle stability through the strengthening exercise of peroneus muscles is considered an important factor for achievement of successful outcomes, in the rehabilitation program following ankle ligament injuries. However, there were few definitive data on normal muscle strength, including eversion power by peroneus muscles. This study was conducted to evaluate the muscle strength of ankle joint measured using an isokinetic dynamometer in normal Koreans. Materials and Methods: Sixty adults (120 ankles) were recruited and divided into three groups (20 in their twenties, 20 in thirties, and 20 in forties). Each group consisted of 10 males and 10 females. The selection criteria were no history of ankle injury and no evidence of instability. The peak torque, total work, and deficit ratio were measured using the Biodex$^{TM}$ (Biodex Medical Systems). Differences in muscle strength by age, gender and dominant versus non-dominant side were analyzed. Results: The peak torque of dorsiflexion was average 31.5 Nm at $30^{\circ}/s$ of angular velocity and 18.8 Nm at $90^{\circ}/s$; average 69.3 Nm ($30^{\circ}/s$) and 42.4 Nm ($90^{\circ}/s$) on plantarflexion; average 19.6 Nm ($30^{\circ}/s$) and 10.8 Nm ($90^{\circ}/s$) on inversion; average 12.9 Nm ($30^{\circ}/s$) and 8.0 Nm ($90^{\circ}/s$) on eversion. The deficit ratio of strength in women was average 61.1% of men on dorsiflexion; average 66.2% on plantarflexion; average 48.5% on inversion; average 55.4% on eversion. The deficit ratio in non-dominant foot was average 88.6% of dominant foot on dorsiflexion; average 90.1% on plantarflexion; average 85.1% on inversion; average 85.6% on eversion. Conclusion: The muscle strength of the ankle joint showed a tendency to weaken with age. There were significant differences in muscle strength by gender and dominancy. Further studies for comparison of patients with ankle instability, a comparison between before and after surgery for instability, the correlation between clinical outcomes and the recovery in muscle strength will be needed.