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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Sport Biomechanics
Journal Basic Information
Journal DOI :
Korean Society of Sport Biomechanics
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Volume & Issues
Volume 19, Issue 4 - Dec 2009
Volume 19, Issue 3 - Sep 2009
Volume 19, Issue 2 - Jun 2009
Volume 19, Issue 1 - Mar 2009
Selecting the target year
REVIEW OF COMPUTATIONAL MODELS FOR FOOTWEAR DESIGN AND EVALUATION
Cheung, Jason Tak-Man ; Yu, Jia ; Zhang, Ming ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 13~25
DOI : 10.5103/KJSB.2009.19.1.013
Existing footwear biomechanics studies rely on simplified kinetics and kinematics, plantar pressure and muscle electromyography measurements. Because of the complexity of foot-shoe interface and individualized subject response with different footwear, consistent results regarding the biomechanical performance of footwear or footwear components can yet be achieved. The computational approach can be an efficient and economic alternative to study the biomechanical interactions of foot and footwear. Continuous advancement in numerical techniques as well as computer technology has made the finite element method a versatile and successful tool for biomechanics researchdue to its capability of modelling irregular geometrical structures, complex material properties, and complicated loading and boundary conditions. Finite element analysis offers asystematic and economic alternative in search of more in-depth biomechanical information such as the internal stress and strain distributions of foot and footwear structures. In this paper, the current establishments and applications of the computational approach for footwear design and evaluation are reviewed.
The Effects of Restricted Trunk Motion on the Performance of Maximum Vertical Jump
Kim, Yong-Woon ; Eun, Seon-Deok ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 27~36
DOI : 10.5103/KJSB.2009.19.1.027
The purpose of this study was to identify effects of restricted trunk motion on the performances of the maximum vertical jump. Ten healthy males performed normal countermovement jump(NJ) and control type of countermovement jump(CJ), in which subjects were required to restrict trunk motion as much as possible. The results showed 10% decreases of jumping height in CJ compared with NJ, which is primarily due to vertical velocity at take off. NJ with trunk motion produced significantly higher GRF than RJ, especially at the early part of propulsive phase, which resulted from increased moments on hip joint. And these were considered the main factors of performance enhancement in NJ. There were no significant differences in the mechanical outputs on knee and ankle joint between NJ and RJ. With trunk motion restricted, knee joint alternatively played a main role for propulsion, which is contrary on the normal jump that hip joint was highest contributor. And restricted trunk motion resulted in the changes of coordination pattern, knee-hip extension timing compared with normal proximal-distal sequence. In conclusion these results suggest that trunk motion is effective strategy for increasing performance of vertical jumping.
A Study about the Training Program for the Kolman Technique on the Horizontal Bars
Back, Jin-Ho ; Park, Jong-Chul ; Yoon, Chang-Sun ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 37~47
DOI : 10.5103/KJSB.2009.19.1.037
This study develops a technique training program to enhance the completion of Kolman, the high air flight technique, and applies it to two national athletes of the horizontal bar, one of the gymnastic events, for eight weeks. After that, their improvement was measured through 3D motion analysis to help them elevate their performance. The training program includes swing, hand release, twist, and bar hold, and its implementation produced the results stated below. They were made to practice the motion in the following way. After the hand-standing of giant swing which initiates the motion, they lift their body upward a little bit more. Next, they take their body down almost like a vertical descent and make a deep tap swing. Instead of doing the tap swing which widens the flection of hip and shoulder joints, while body revolution is more emphasized in particular, they release the bar as raising the centroid of their body sufficiently. During the flight, they try to narrow every joint in their body. As a result, the bar`s elasticity becomes greatly increased, and since the backing rate of their body gets higher, the centripetal force of the swing is improved that they can release the bar in the higher position. In addition, because they can erect their body faster during the flight, they can perform comfortable twist and revolution in the air. They can also adjust the direction of the flight easily without too much concern for the proper timing of hand release as they rise. Thereby, they can not only maintain adequate distance from the bar for the bar hold but also ensure enough distance for body revolution and twist.
Association between the C.O.G and E.O.G for Dynamic Postural Control of the Left Turn Motion on the Balance Beam
So, Jae-Moo ; Kim, Yoon-Ji ; Kim, Jae-Jung ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 49~58
DOI : 10.5103/KJSB.2009.19.1.049
This study aims to analyze the association between the center of mass(C.O.G) and ocular movement(E.O.G) according to the success and failure in the left turn motion on the balance beam, targeting three female gymnasts. When successful, the left-right C.O.G was moved to the left, which was a rotational direction until such time as the body rotated
, whereas there appeared to be a greater movement during failure; thus, it was shown to affect the maintenance of dynamic postural control. In case of the subsequent left-right turning motion of E.O.G, this matches the previous theory that the eyeball moves against the direction of rotation of the body. However, there was a difference at the time of movement, and a clear difference emerged in the success and failure in this study. Also, in the E.O.G in the up-down direction, a movement during failure showed a pattern of down direction in most cases; thus, it is deemed to affect the failure. Therefore, the kinetic postural control and E.O.G are supposed to affect the success and failure in a landing, which is the most importantly evaluated movement on the balance beam, in mutual association.
The Analysis of Swing Plane of Elite Golfers During Drive Swing
Lim, Young-Tae ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 59~66
DOI : 10.5103/KJSB.2009.19.1.059
The purpose of this study was to evaluate flatness of swing plane and determine swing plane type using 3-D swing plane analysis from young elite male golf players. This study also investigate the possibility of determination of swing plane using other kinematic parameters except flatness. As results, no correlations was found between flatness and handicap. Comparison of flatness between single plane and multiple plane swing group were performed and found a significant difference. The error range of flatness, 10cm, which was used for distinguish swing plane type was effective since significant differences were found at MB, EB, and EF. These differences were typical characteristics to classify two swing styles. Other kinematic parameters such as unit vector components of shaft and displacement of shaft end point also compared per event but found no significant differences. However, the moving patterns of these parameters during a golf swing showed such characteristics of each swing plane type well that these parameters could be used to determine swing style as an indirect barometers.
The Effects of Target Position on the Bowling Motion
Kim, Min-Soo ; Back, Jin-Ho ; Kwak, Chang-Soo ; Lee, Ki-Chung ; Park, Jong-Chul ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 67~75
DOI : 10.5103/KJSB.2009.19.1.067
The purpose of this study is to analyze the effects of target position on the bowling motion. Four female high school athletes with more than four years of bowling experiences were recruited to this study. The major results of this study are as follows; When a subject treats the 1st pin, The spin angle of a coxa for the target position is largely kept from the downswing to the backswing peak point. When a subject treats the 7th pin, As the 7th pin exists at the left side for the right shoulder axis of the thrower, the movement of the ball center of the thrower from side to side is the lowest. In addition, the time required and horizontal speed appear the highest in the release section. The slant angle of a shoulder is largely increased as she moves from the backswing peak point to the release section. The twist angle of a shoulder also appears small as a throw motion is made toward the left side. When a subject treats the 10th pin, The spin angle of a shoulder and the twist angle of a body in motion appear the largest in the release section. So, there are the effects of target position on the bowling motion.
Kinematic Analysis of the Badminton Drive Motion
Wei, Lin-Lin ; Oh, Cheong-Hwan ; Jeong, Ik-Su ; Park, Chan-Ho ; Lee, Jeong-Tae ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 77~85
DOI : 10.5103/KJSB.2009.19.1.077
This study is aimed at providing information on injury prevention and skill improvement by inducing the accurate movements in exercise as well as understanding the principles of badminton drive movements. Movement displacement of racket head showed the similar patterns among those surveyed but, it seemed that slight differences resulted from external factors such as height, length of brachial and forearm and individual trend of swing locus. Regarding upper joint angle per phase, the angles of shoulder joint, elbow joint and wrist joint were closely associated in taking drive movements and they supported the segment order theory that power was conveyed from proximal into distal. It was shown that angular velocity of upper joint became larger in follow through movement after impact among all those surveyed, which meant the importance of follow through in racket sports such as badminton. In conclusion, this follow through movement acts as an important factor in racket sports in terms of pose stability maintenance, pose correction of movements and injury prevention of joints. In summary, when swings are made according to segment order theory, efficient movements can be taken.
Biomechanical Analysis of Throwing Movement between Skilled and Unskilled High School Students
Kough, Hyung-Jeek ; Ju, Myung-Duck ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 87~98
DOI : 10.5103/KJSB.2009.19.1.087
This study was conducted to compare biomechanical differences in throwing movement between skilled and unskilled high school students using three-dimensional analysis system with a force platform. The findings indicated that skilled students showed shorter throwing time, faster horizontal speed of (1) the center of mass at heel contact of left foot, (2) the forearm throughout swing phase, (3) the hand after heel contact while unskilled students showed faster horizontal speed of, (1) the center of mass after heel contact and (2) the hand at heel contact of left foot. Skilled students showed greater (1) shoulder angle during throwing, (2) elbow angle after take off of foot, (3) peak vertical ground reaction force during throwing and (4) peak anterior-posterior ground reaction force at heel contact of right foot. While skilled students showed leaning backward of the trunk during throwing, unskilled students showed leaning forward during release phase with leaning backward before release.
The Effect of female Hormone on Knee Joint Laxity
Park, Sang-Kyoon ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 99~106
DOI : 10.5103/KJSB.2009.19.1.099
The purpose of this study was to determine whether hormone levels change knee laxity in healthy females. Twenty three healthy females were recruited for the study. Serum estradiol and progesterone levels were recorded three times during the subjects` menstrual cycles. The first measurements were taken between day 3 and 7 of the follicular phase and the second data collection coincided with ovulation, 24 to 48 hours after the estrogen surge detected by an ovulation predictor kits. Based on a 28 day cycle, the third data collection occurred approximately 7 days later during the luteal phase. Knee joint laxity was recorded at the same intervals with a KT 2000 arthometer. Hormone levels and phases were compared to passive knee joint laxity with multiple regression analysis. Estradiol and progesterone levels differed significantly across the three tests. Knee joint laxity increased during ovulation. Based on a multiple regression analysis, estradiol and progesterone levels predicts 77.9% to 80.9% of the laxity at 20lb and 30lb loads. An antagonistic relationship between estradiol and progesterone was found when testing for knee laxity. Serum hormone levels have moderate power in predicting knee joint laxity. Individual hormonal profiling in female athletes would allow researchers to access the structural properties of the ACL, such as the laxity which may provide beneficial information to understand female ACL injury mechanism in sports activity.
The Effects of Muscle, Balance and Walking Training on Gait Kinematics in Children with Down Syndrome
Lim, Bee-Oh ; Kim, Kye-Wan ; Yu, Yeon-Joo ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 107~115
DOI : 10.5103/KJSB.2009.19.1.107
The purpose of this study were to investigate the effects of muscle, balance and walking training on muscle, balance and gait kinematics in children with Down syndrome. Nine children (
years old) with Down syndrome participated in this study. The participant with Down syndrome participated in muscle, balance and walking training for 12 weeks, three times a week Kinematic variables of gait were measured 3-dimentional motion capture system. The results indicated that the pelvis rotation decreased, the knee and hip flexion increased, decreased leg sway during the swing phase, the cadence increased, and the stride length decreased after the muscle, balance and walking training. In conclusion, Down syndrome`s gait kinematic variables improved after the muscle, balance and walking training.
Effects of 12-Week Complex Training Program on Foot-Pressure Patterns of the Elderly Women
Lee, Joong-Sook ; Yang, Jeong-Ok ; Lee, Bom-Jin ; Park, Sang-Mook ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 117~126
DOI : 10.5103/KJSB.2009.19.1.117
The purpose of this study was to investigate the effects of 12-week complex training program on foot pressure patterns of the elderly women. The training program consisted of aerobic exercise and muscular training for 12 weeks. Two stages of walking were given to the participants before and after treatment: (a) straight walking; and (b) turn at
while walking. Data related to foot-pressure distribution(FPD) while walking were collected from each stage and analyzed. Results indicated that in both stage of walking, the mean of the foot pressure(FP) was significantly reduced after the participation in the program. Results also revealed that in all stages, the patterns of the FPD and the center of pressure(COP) were widely lower and more stable. Based on the results of this study, it was concluded that participating in a 12-week complex program bas impact on the gait patterns of the elderly women, reducing the foot pressure on their shoes.
Comparison of ROM and Muscle Activities According to the Skills of Surya Namaskara in Vinyasa Yoga
Hong, So-Yoen ; Park, Jin ; Hah, Chong-Ku ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 127~138
DOI : 10.5103/KJSB.2009.19.1.127
The purpose of this study was to investigate range of motion (ROM) and muscle activities according to the skills of Surya Namaskara in Vinyasa Yoga. Six females (skilled 2, unskilled 4) of university students participated in this experiment. The research factors were ROM and muscle activities for static poses on Surya Namaskara in Vinyasa Yoga. The six infrared cameras (Oqus 300, Qualisys Inc, Sweden) and Zero Wire EMG (Aurion, Italy) were used to acquire raw data, and the Qualisys Track Manager and Noraxon (MyoResearch XP Master Edition, USA) were used to process data. The %MVIC and ROM were analyzed with Visual 3D (C-Motion Inc, USA) and Noraxon. In conclusion, ROM and %MVIC between two groups were remarkable different according to the static poses of Yoga, therefore instructors have to provide step-by-step information that was suitable to themselves (ROM and EMG of poses).
Effects of Combined Resistance Training Program of Concentric and Eccentric Contraction Using Theraband on Shoulder Rotation Torque Max and Peak Power
Han, Dong-Wook ; Ahn, Yi-Rae ; Lee, Na-Jung ; Lee, Eun-Ju ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 139~148
DOI : 10.5103/KJSB.2009.19.1.139
The purpose of this study was to find out that combined concentric with eccentric resistance training program using Thera-Band was more effective than only concentric resistance training program on shoulder rotation torque max and peak power. 30 female students were randomly assigned to 3 equal group; concentric and eccentric, concentric, non training group. Subjects were tested in concentric and eccentric torque max and peak power of internal and external rotation using a CON-TERX isokinetic dynamometer. Subjects in training group participated in their regular five times a week for 4 weeks. After exercise, in concentric and eccentric training group, concentric and eccentric torque max, and peak power of internal rotator at 60 deg/sec were increased significantly. concentric peak power at 120 deg/sec were increased significantly. In concentric training group, only concentric peak power of internal rotator at 60 and 120 deg/sec was increased. In conclusion, we found out that combined concentric with eccentric resistance training program using Thera-Band was more effective than only concentric resistance training program on shoulder rotation torque max and peak power.
Biomechanical Testing and Evaluation for Korean Badminton Shoes Project(I)
Park, Seung-Bum ; Park, Sang-Kyoon ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 149~157
DOI : 10.5103/KJSB.2009.19.1.149
The purpose of this project was to determine biomechanical differences between Type A(Korean brand) and Type B(world top brand) badminton shoes and to make recommendations to improve the fit and function of Type A badminton shoes. Measurements of shoe shape and dimensions, foot movement within the shoe, cushioning of ground reaction forces, in-shoe pressure and outsole traction were performed. In addition, subjective feedback of the fit and function of the shoes was quantified for 17 recreational badminton players. Type A shoe had a much higher heel and shallower heel cup, so the heel was not secured well in the shoe and the ankle joint was higher off the ground. Foot slippage was up to 40% greater in Type A shoe than Type B shoe. Impact forces and peak pressures under the foot were generally higher with Type A shoe compared to Type B shoe. The flexion axis of Type A shoe occurred in the midfoot, not at the ball of the foot like Type B shoe, where you would want the shoe flexion to occur. In summary, there are several characteristics where A Type shoe and B Type differ. Therefore, a few recommendations are provided to help improve the fit and function of A Type shoe.
Development of Gait Event Detection Algorithm using an Accelerometer
Choi, Jin-Seung ; Kang, Dong-Won ; Mun, Kyung-Ryoul ; Bang, Yun-Hwan ; Tack, Gye-Rae ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 159~166
DOI : 10.5103/KJSB.2009.19.1.159
The purpose of this study was to develop and automatic gait event detection algorithm using single accelerometer which is attached at the top of the shoe. The sinal vector magnitude and anterior-posterior(x-axis) directional component of accelerometer were used to detect heel strike(HS) and toe off(TO), respectively. To evaluate proposed algorithm, gait event timing was compared with that by force plate and kinematic data. In experiment, 7 subjects performed 10 trials level walking with 3 different walking conditions such as fast, preferred & slow walking. An accelerometer, force plate and 3D motion capture system were used during experiment. Gait event by force plate was used as reference timing. Results showed that gait event by accelerometer is similar to that by force plate. The distribution of differences were spread about
for HS and
for To and most error was existed consistently prior to 20ms. The difference between gait event by kinematic data and developed algorithm was small. Thus it can be concluded that developed algorithm can be used during outdoor walking experiment. Further study is necessary to extract gait spatial variables by removing gravity factor.
Effect of Golf Shoe Design on Kinematic Variables During Driver Swing
Park, Jong-Jin ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 167~177
DOI : 10.5103/KJSB.2009.19.1.167
The purpose of this study was to investigate effect of golf shoe design on kinematic variables during golf swing. Five professional male golfers with shoe size 270mm were recruited for the study. Swing motion was collected using 8 high speed camera motion analysis at a sampling of 180Hz. Kinematic variables were calculated by EVaRT 4.2 software. Driver swing was divided into four events; El(adress), E2(top), E3(impact) and E4(finish). Time, peak velocity, velocity of center of mass, velocity of the foot and ankle angle during Phase 1(El-E2), Phase 2(E2-E3), and Phase 3(E3-E4) were analyzed in order to investigate the relationship between golf shoe design and swing performance. The findings indicated that type C golf shoes would be beneficial for stability and control of movement during address and swing performance. Furthermore, faster speed of golf shoes, center of mass, and both feet were observed with Type C golf shoes. It is expected that golfers with Type C golf Shoes provide greater force as they control the center of mass faster and increase rotational force during impact compared to other golf shoes.
A Study on the Estimation Accuracy of Energy Expenditure by Different Attaching Position of Accelerometer
Kang, Dong-Won ; Choi, Jin-Seung ; Mun, Kyung-Ryoul ; Bang, Yun-Hwa ; Tack, Gye-Rae ;
Korean Journal of Sport Biomechanics, volume 19, issue 1, 2009, Pages 179~186
DOI : 10.5103/KJSB.2009.19.1.179
This works studied to compare gas analyzer with accelerometer and the estimation of energy expenditure based on different attaching position of tri-axial accelerometer such as waist and top of the foot Based on the fact that oxygen intake increases more radically linearly during walking more than 8.0km/hr. 9 male subjects performed walking and running on the treadmill with speed of
/hr, respectively. Commercially available Nike + iPod Sports kit was used to compare energy expenditure with sensor module attached to their foot. Actual energy expenditure was determined by a continuous direct gas analyzer and two multiple regression equations of walking and running mode for different attaching position were developed. Results showed that estimation accuracy of energy expenditure using waist mounted accelerometer was higher than that of the top of the foot and Nike + iPod Sports kit. Results of energy expenditure based on waist and top of the foot showed that the crossover state of energy expenditure occurred at 7.5km/hr. But Nike + iPod Sports kit could not find intersection of energy expenditure in all nine subjects. Therefore the sensor module attached to the waist and separate multi regression equation by walking and running mode was the best to estimate more accurate prediction.