• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.81-86
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• 2010

Despite the importance of cycling postures during cycling performances, there has been a very little research investigating cycling postures and pedaling rate for particularly concerning domestic cyclists. The aim of this study was to analyze correlations and effects between cycling postures and pedaling rate in track cycling. Twelve male racing cyclists (six racing and university cyclists) participated in this research. For this study, seven infrared cameras (Qualisys ProReflex MCU-240s) were used for collecting data and these were processed via QTM (Qualisys Tracker Manager) software. It appeared that pedaling rate had correlations with regard to a shoulder angle (R=-.601) and displacement between shoulder joints(R= -.637), but a knee (R=-.601) and ankle angle (R=.667). Moreover, two multiple regression equations of pedaling rate for cycling postures were significant and R2 of the first order equation y (pedaling rate) = 0.039x (knee angle) - 1.068 was less than the second order equation y = 0.006x2 - 1.287x + 69.674. In conclusion, cycling postures affected the pedaling rate. Further study should be researched on postures in relation to air resistance in a wind tunnel.

• Physical Therapy Korea
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• v.29 no.4
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• pp.262-268
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• 2022

Background: Virtual reality (VR) programs based on motion capture camera are the most convenient and cost-effective approaches for remote rehabilitation. Assessment of physical function is critical for providing optimal VR rehabilitation training; however, direct muscle strength measurement using camera-based kinematic data is impracticable. Therefore, it is necessary to develop a method to indirectly estimate the muscle strength of users from the value obtained using a motion capture camera. Objects: The purpose of this study was to determine whether the pedaling speed converted using the VR engine from the captured foot position data in the VR environment can be used as an indirect way to evaluate knee muscle strength, and to investigate the validity and reliability of a camera-based VR program. Methods: Thirty healthy adults were included in this study. Each subject performed a 15-second maximum pedaling test in the VR and built-in speedometer modes. In the VR speedometer mode, a motion capture camera was used to detect the position of the ankle joints and automatically calculate the pedaling speed. An isokinetic dynamometer was used to assess the isometric and isokinetic peak torques of knee flexion and extension. Results: The pedaling speeds in VR and built-in speedometer modes revealed a significantly high positive correlation (r = 0.922). In addition, the intra-rater reliability of the pedaling speed in the VR speedometer mode was good (ICC [intraclass correlation coefficient] = 0.685). The results of the Pearson correlation analysis revealed a significant moderate positive correlation between the pedaling speed of the VR speedometer and the peak torque of knee isokinetic flexion (r = 0.639) and extension (r = 0.598). Conclusion: This study suggests the potential benefits of measuring the maximum pedaling speed using 3D depth camera in a VR environment as an indirect assessment of muscle strength. However, technological improvements must be followed to obtain more accurate estimation of muscle strength from the VR cycling test.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.537-543
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• 2017

The purpose of this research is to investigate the effects of different shoe-cleat position on pedalling performance. Four male elite triathletes(age: $22.00{\times}2.16years$, height: $175.12{\pm}8.06cm$, weight: $71.20{\pm}7.89kg$, body fat: $16.62{\pm}3.56%$) and three female elite triathletes(age: $20.00{\pm}1years$, height: $158.40{\pm}2.42cm$, weight: $51.30{\pm}3.89kg$, body fat: $19.26{\pm}2.28%$) participated in 10km time trial and 30sec time trial pedaling tests with the individual time trials based on different shoe-cleat position(cleat front: CF, cleat back: CB). The subjects performed one trial with each type of shoe-cleat position. Maximal power output and average speed were not significantly different during 30s time trial in CF compared with CB. Average power, RPM, and HR were not significantly different during 10k time trial in CF compared with CB. Split time in 1km, 5km, 9km were significantly reduced during 10k time trial in CB compared with CF. We conclude that there was performance advantage in CB using shoe-cleat back position in comparison with CF using shoe-cleat front position.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.9
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• pp.753-760
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• 2016

This study was undertaken to develop a bed-type cycling system of lower limbs for rehabilitation. This system consists of two modes of cycling: active and passive. Different velocity and loads are provided for improving the muscle function recovery and increasing the muscular strength. To analyze the muscle activity pattern, we measured muscular activity of lower limbs in the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), medial gastrocnemius (MG), and soleus (SOL), while cycling in the supine position, and based on the pedaling direction. A total of 18 young and 23 elderly, healthy subjects participated in this study. Muscle activity of MG muscles was significantly different in the two age groups. This study could provide the reference data to develop cycling exercises for lower limbs during rehabilitation of the elderly patients.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.75-83
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• 2005

The purpose of this study was to determine the kinematic characteristics of the ankle joint and RPM(repetition per minutes) during the supra maximal training in cycling. For this study, 8 national representative cyclists, distance cyclists in track and road, were selected. During the super-maximum pedalling, kinematic data were collected using a six-camera(240Hz) Qualisys system. the room coordinate system was right-handed and fixed in the back of a roller for cycle, with right-handed orthogonal segment coordinate systems defined for the leg and foot. Lateral kinematic data were recorded at least for 3 minutes while the participants pedal on a roller. Two-dimensional Cartesian coordinates for each marker were determined at the time of recording using a nonlinear transformation technique. Coordinate data were low-pass filtered using a fourth-order Butterworth recursive filter with cutoff frequency of 15Hz. Variables analyzed in this study were compared using a one factor(time) ANOVA with repeated measures. The results of investigation suggest that the number of rotating pedal was decreased with time phase during the super-maximum pedaling. Maximum angle of the ankle joint showed little in change with time phase compared with minimum angle of that.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.123-129
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• 2012

Simple camera-based system for evaluation of lower limb alignment as a part of an automated cycling fitting system was developed and verified in this study. Developed imaging system can evaluate lower limb alignment quantitatively during pedaling using a general camcorder and single marker attached on the knee. Threshold-based marker detection algorithm was proposed in this study. Experiment was carried out to compare the trajectory data from marker detection algorithm of the developed imaging system with the trajectory data from 3-D motion capture system. Results showed that average error between trajectories was 2.33 mm (0.92 %) in the vertical direction and 0.62 mm (1.86 %) in the medio-lateral direction. There existed significant correlation between two measured values (r=0.9996 in the vertical direction and r=0.9975 in the medio-lateral direction). It can be concluded that developed imaging system be applied to evaluate lower limb alignment which is an important factor for dynamic bicycle fitting.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.604-609
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• 2002

In development of an advanced bicycle simulator, the investigation of the interactions between bicycle and rider during cycling is paramount important because bicycle is a two-wheeled human-powered vehicle. Tn this work, the tilt stability. among various interactions, of bicycling is investigated experimentally, In the experiments, the tilt angles of the bicycle, riders body and head are measured, as the riding p;1th and the speed are varied. Subjects are asked to ride along four typical paths on rigid flat ground : the straight, C-curved, S-curved and circle paths. The results from extensive experiments with different subjects can be summarized as : 1) The tilt angles of bicycle and rider are almost out of phase during pedaling along the straight path. 2) The bicycle tilt angle is nearly proportional to the square of bicycle speed for the straight and curved paths, and to the curvature for the curved paths. The head tilt angle is the biggest and the body tilt angle is the smallest for the straight path, but the tendency is reversed for the C-curved path. During the curve maneuvering, the rider's head tends to tilt by less than 40% of the bicycle tilt angle.

• Journal of the Korea Safety Management & Science
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• v.12 no.1
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• pp.51-57
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• 2010

Cycling that transform human energy into mechanical energy is one of the man-machine systems out of sports fields. Benchmarking means "improving ourselves by learning from others', therefore benchmarking toward dominant cyclist is necessary on field. The goals of this study were to provide important factors on multi-disciplines (kinematics, physiology, power, psychology) for a tailored-training program that is suitable to individual characteristics. Two cyclists participated in this study and gave consent to the experimental procedure. One was dominant cyclist (years: 21 yrs, height: 177 cm, mass: 70 kg), and the other was non-dominant cyclist (years: 21, height: 176, mass: 70). Kinematic data were recorded using six infrared cameras (240Hz) and QTM (software). Physiological data (VO2max, AT) were acquired according to graded exercising test with cycle ergometer and power with Wingate test used by Bar-Or et. al (1977) and to evaluate muscle function with Cybex. Psychological data were collected with competitive state anxiety inventory (CSAI-2) that was devised by Martens et. al (1990) and athletes' self-management questionnaire (ASMQ) of Huh (2003). It appears that the dominant's CV of ankle joint angle was higher than non-dominant's CV and dominant's pedaling pattern was consistent in biomechanics domain, which the dominant's values for all factors ware higher than non-dominant's values in physical, and physiological domain, and their values between cognitive anxiety and somatic anxiety were contrary to each other in psychology. Further research on multi-disciplines may lead to the development of tailored-optimal training programs applicable with key factors to enhance athletic performance by means of research including athlete, coach and parents.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.4
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• pp.331-337
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• 2015

This research was to develop the cycling system of lower limbs for rehabilitation during cycle exercise in supine position. Also we analyzed the muscular activity of lower-limbs at various exercise conditions according to exercise mode, load, velocity. 42 healthy subjects(ages 20-60 years) were participated. We measured the muscular activities of right lower limb muscle in rectus femoris, biceps femoris, tibialis anterior, medial gastrocnemius, soleus. Results, medial gastrocnemius shows high value on load 10 stage than load 1 and 5 stage. And all muscular activity except medial gastrocnemius was decreased as increase of velocity. We have found that there is a difference of lower limbs activity depending on exercise mode and method. This study could be applied to reference data to develop cycle system of lower limbs for rehabilitation.