• 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.

• 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 Korea Society of Computer and Information
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• v.24 no.5
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• pp.93-102
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• 2019

The nation's fraternity and elite players who have built up a global bicycle infrastructure often find it to be a problem with the bicycle's speed and speed reduction, pain in knees and hip joints, or even with the bike itself, or with the bike's own physical defects or a riding posture. However, we found that most cases of cleat adjustment errors were likely to be true. Accurate adjustment of the cleats is the most important of the entire fitting process and can be the basis for improving the ability of the bicycle rider and preventing injury. Therefore, the study was intended to give a prior study of bicycle fitting, which can improve bicycle efficiency and prevent injury when riding bicycle, and specific ways of adjusting bicycle shoe cleats, and the following results were obtained. First, the cleat characteristics of Shimano, LOOK and Speedplay, which are currently used in public, and the characteristics during the cleat adjustment process, were derived. In addition, the structure and characteristics of dedicated shoes using cleats and the method of using pedalling by the structure of shoes after adjusting the cleats were derived. Second, the position of the shoe and its relationship with torque in pedalling was discussed, and the method of adjusting front and back of cleats was derived. Third, leg length, ASIS, Q-Angle and Q-factor etc. were analyzed and the method of setting and adjusting cleat left and right values were derived. Fourth, the relationship between walking angle and cleat rotation was analyzed, the method was derived, and the torque size and angle behind the cleat adjustment were compared and analyzed using the spinner to indicate the torque and the effective mean torque angle after the cleat adjustment.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.8-12
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• 2017

Bicycles are very popular sporting goods in these days. Thus, the durability of bicycles is very important for the safety of bicyclists. It is well known that a bicycle frame is a major component which is essential to the safety and performance of a complete bicycle. In this study, the durability of bicycle frames were experimentally investigated under the fatigue load. Eighty bicycle frames with different types and materials were prepared and tested according to EN standards. Three kinds of fatigue loads, that is, pedalling, vertical and horizontal fatigue load, which occur constantly during riding a bicycle, were applied to the bicycle frames. The experimental results show that the horizontal fatigue load was the severest mode to pass EN standard. The pass ratio of horizontal fatigue load test was 45.2%, while the pass ratio of vertical fatigue load test was 100%. Most of cracks were found at the right side of bottom bracket shell and at the intersection area between head tube and down tube. It seems that the experimental results can be applied to improve the safety and performance of a bicycle frame.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.1-5
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• 2013

In order to evaluate fatigue endurance for an MTB(mountain bike) frame, FEM(finite element method) analysis was performed. For evaluating the fatigue endurance of the MTB frame, the S-N data for Al-6061 fillet weldment were compared with the stress analysis results through FEM analysis of the frame. Three loading condition, pedalling, horizontal and vertical loading conditions were considered for fatigue endurance evaluation. Horizontal loading(+1200 N) condition was found to be the most severe to the frame. The maximum von Mises stress of the frame under horizontal loading(+1200 N) condition was determined 294 MPa through FEM analysis of the frame. Conclusively, on the basis of fatigue strength of 200 MPa at the number of cycles of 50,000, the MTB frame has an improper safety factor of approximately 0.25, suggesting that this frame needs reinforcement.

• 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.

• Journal of muscle and joint health
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• v.7 no.1
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• pp.102-130
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• 2000

The aims of this study were to understand and to predict the determinant factors affecting the exercise behaviors and physical fitness by testing the Ponder's health promotion model, and to help the patients with rheumatoid arthritis and osteoarthritis perform the continuous exercise program, and to help them maximize the physical effect such as muscle strength. endurance, and fuctional status and mental effects including self efficacy and quality of life, and improve the physical and mental wellbeing, and to provide a basis for the nursing intervention strategies. We analyzed the clinical records of 208 patients with rheumatoid arthritis and degenerative arthritis who visited the outpatient clinics at H university hospital in Seoul between October 5, 1999 and October 24, 1999. Data were composed of self reported questionnaire and good of fitness score which were obtained by pedalling the ergometer of bicycle for 9 minutes. SPSS Win 8.0 and Window LISREL 8.12a were used for statistical analysis. 24 Of 54 hypothetical paths were supported in modified model, which was considered as a proper model with improved fit index. The physical fitness was directly influenced by exercise participation behavior and education level, and indirectly by physical fitness, while fatigue, physical disability, pastexercise behavior, life-style, self-efficacy, which explained 20% of physical fitness. The exercise participation were directly influenced by perceived benefits and self-efficacy, and indirectly influenced by life-style, fatigue and physical disability, and directly and indirectly by past exercise behavior, which explained 53% of exercise participation. Exercise score were directly affected by perceived health status, perceived benefits, self efficacy, and past exercise behavior, and were indirectly affected by fatigue, physical disability, and life-style, which explained 50%. Perceived health status were directly influeced by level of education, depression, sleep disorder, and physical disability, which explained 34% of perceived health status. Perceived benefit was directly influenced by fatigue, sleep disorder, physical disability, and life-style, which explained 45%. Perceived barriers was directly influenced by fatigue, sleep disorder, and lifestyle, which explained 9%. Self- efficacy was directly influenced by fatigue, physical disability, past exercise behavior, and level of education, which explained 61%. In conclusion, important variables for physical fitness were exercise participation and level of education, and variables affecting exercise participation were perceived self-efficacy, benefits, and past exercise behavior. Perceived self-efficacy of exercise was a significant predictor of exercise participation. Life-style, fatigue, and physical disability showed direct effects on perceived benefit, perceived barriers, and self-efficacy, and indirect effects on exercise behavior. Therefore, disease related factor should be minimized for physical performance and well being in nursing intervention for patients with rheumatoid arthritis, and plans to promote and continue exercise should be soaked to reduce disability. In addition, Exercise program should be planned and performed by the exact evaluation of exercise according to the ability of the patients and the contents to improve the importance of exercise and self efficacy in self control program, dedicated educational program should be involved.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.181-187
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• 2014

In this study, a real-time evaluation system for quantitative dynamic fitting during pedaling was developed. The system is consisted of LED markers, a digital camera connected to a computer and a marker detecting program. LED markers are attached to hip, knee, ankle joint and fifth metatarsal in the sagittal plane. Playstation3 eye which is selected as a main digital camera in this paper has many merits for using motion capture, such as high FPS (Frame per second) about 180FPS, $320{\times}240$ resolution, and low-cost with easy to use. The maker detecting program was made by using Labview2010 with Vision builder. The program was made up of three parts, image acquisition & processing, marker detection & joint angle calculation, and output section. The digital camera's image was acquired in 95FPS, and the program was set-up to measure the lower-joint angle in real-time, providing the user as a graph, and allowing to save it as a test file. The system was verified by pedalling at three saddle heights (knee angle: 25, 35, $45^{\circ}$) and three cadences (30, 60, 90 rpm) at each saddle heights by using Holmes method, a method of measuring lower limbs angle, to determine the saddle height. The result has shown low average error and strong correlation of the system, respectively, $1.18{\pm}0.44^{\circ}$, $0.99{\pm}0.01^{\circ}$. There was little error due to the changes in the saddle height but absolute error occurred by cadence. Considering the average error is approximately $1^{\circ}$, it is a suitable system for quantitative dynamic fitting evaluation. It is necessary to decrease error by using two digital camera with frontal and sagittal plane in future study.