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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
Editor in Chief :
Jae Moo So
Volume & Issues
Volume 20, Issue 4 - Dec 2010
Volume 20, Issue 3 - Sep 2010
Volume 20, Issue 2 - Jun 2010
Volume 20, Issue 1 - Mar 2010
Selecting the target year
The Validity Test of Upper·Forearm Coordinate System and the Exploratory Analysis of the Interactive Effect between Flexion/Extension and Pronation/Supination during Elbow Joint Motion
Kim, Jin-Uk ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 117~127
DOI : 10.5103/KJSB.2010.20.2.117
The axes of upper forearm coordinate system have been considered as principal axis of each segment which was component of elbow joint. The purpose of this study was to verify whether the mean direction(principal axis) of instantaneous axes of rotation for pure flexion/extension motion coincided with the flexion/extension axis of upper forearm coordinate system. The same procedure was done for pronation/supination motion. Furthermore, it was tested indirectly that there was an interaction effect between the two rotational motions. The results showed that most segment coordinate axes statistically were not consistent with the mean directions of flexion/extension and pronation/supination axes of rotation. From the results, it would be concluded that the ISB coordinate systems was proved to be a little valid for human movement analysis. There also was an effect of pronation/supination angles on flexion/extension motion.
The Kinetic and Kinematic Effect of a 12-week Aquatic Exercise Program on Obstacle Gait in Older Women
Choi, Pyoung-Hwa ; Yoon, Suk-Hoon ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 129~137
DOI : 10.5103/KJSB.2010.20.2.129
The purpose of this study is to investigate the effect of a 12-week aquatic exercise on obstacle gait in older women. Originally, 20 healthy female elderly participated this study but 12 of them completed the program. All participants were trained in the aquatic exercise program by an authorized trainer. They had come to the authors` lab three times during training period(0, 6, 12 weeks) and performed obstacle gait with three different height(0, 30, and 50% of leg length). After performed 3-Dimensional motion analysis following results were found. (1) For the CV, MVHC, TC, HC, statistically significances were shown in obstacle height. Although significant training effects were not shown, all variables showed typical patterns and it was considered as efficient motion to overcome the height obstacles. (2) The anterior-posterior and vertical GRF of support leg during support phase were revealed in height effect but in training one. However, differences between Peak 1 and Peak 2 in vertical GRF increased as training period increased. (3) Knee and hip resultant joint moments were affected by training but ankle resultant moments remained unchanged.
A Kinematic Comparison between the Racquetball Backhand and Squash Backhand Strokes
Kim, Seoung-Eun ; Kim, Seung-Kwon ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 139~148
DOI : 10.5103/KJSB.2010.20.2.139
The purpose of this study was to comparatively analyze the kinematic variables between the squash backhand and racquetball backhand strokes through three-dimensional cinematography. Three expert racquetball players and three expert squash players were involved in the data gathering process. The horizontal, vertical and lateral displacement of racket and trunk segment, intersegmental angular velocity of the wrist, elbow and shoulder joints, and the linear velocity of the racket were descriptively analyzed, and the followings were concluded. The racket of the squash backhand stroke showed an `U` shaped movement where the racket moved rapidly downward and moved forward to make an impact and followed through to a front-top finish, while the racket of racquetball backhand stroke showed an `O` shaped movement where the racket showed circular movement through the rear and bottom positions for the impact, and showed rotation through the lower-front and upper front to a upper-rear-ward finish during the follow-through. The peak velocity of racket was found before the impact point in the squash backhand stroke and at the impact point in the racquetball backhand stroke. For the final conclusion, for the squash backhand stoke, instructors might be better to make the racket move downward to make highest velocity before the impact and finished short follow-through, while for the racquetball backhand stroke, to make the racket move forward to make highest velocity at the impact and finished rather long follow-through.
Effect of Intentional Draw & Fade Shots on Golf Swing Mechanics
Sohn, Jee-Hoon ; Ryue, Jae-Jin ; Lee, Ki-Kwang ; Lim, Young-Tae ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 149~154
DOI : 10.5103/KJSB.2010.20.2.149
Intentional draw and fade shots could be good weapons for lowering golf score. But how to make such shots? To investigate deterministic variables generating different projectile paths of shots in square stance was the purpose of this study. Ten right-handed male collegiate athletes, showing 1.3 of averaged handicap, participated in this study. They were asked to intentionally perform three different shots such as the straight shot(control condition), draw shot, and fade shot. Swing path, pelvis rotation angle, thorax rotation angle and left forearm supination angle were determined for dependent variables on impact event at each trial. For statistical analysis one-way repeated measures ANOVA were used. The results showed that swing path was one of main factor making differences among three kind of shots. Straight shot vs. Draw shot, Straight shot vs. Fade shot and Draw shot vs. Fade shot showed differences on swing path. And left forearm supination angle revealed significant difference between draw shot and fade shot, showing a significant larger angle of draw shot than fade shot. No other significant difference was detected for the other variables. We found that the shot characteristics were influenced primarily by swing path and left forearm supination angle.
Kinematic and Ground Reaction Force Analyses of the Forehand Counter Drive in Table Tennis
Lee, Young-Sik ; Lee, Chong-Hoon ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 155~165
DOI : 10.5103/KJSB.2010.20.2.155
The purpose of this study was to analyze kinematic quantitative factors required of a forehand counter drive in table tennis through 3-D analysis. Four national table tennis players participated in this study. The mean of elapsed time for total drive motion was
. At the phase of impact B1 was the fastest as 0.075 s. This may affect efficiency in the initial velocity and spin of the ball by making a powerful counter drive. The pattern of center of mass showed that it moved back and returned to where it was then moved forward. At the back swing, lower stance made wide base of support and a stronger and safer stance. It may help increasing the ball spin. Angle of the elbow was extended up to
at the back swing and the angle decreased by
at impact. Decreased rotation range of swinging arm increased linear velocity of racket-head and impulse on the ball. Eventually it led more spin to the ball and maximized the ball speed. Angle of knee joint decreased from ready position to back swing, then increased from the moment of the impact and decreased at the follow thorough. The velocity of racket-head was the fastest at impact of phase 2. Horizontal velocity was
and vertical velocity was
at the moment. It may help increase the speed and spin of the ball in a moment. The means of each ground reaction force result showed maximum at the back swing(E2) except A2. Vertical ground reaction force means suggest that all males and females showed maximum vertical power(E2), The maximum power of means was
for male players and
for female players.
Ground Reaction Force and Foot Pressure Analysis During Golf Iron Swing by Gender
Park, Jae-Young ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 167~174
DOI : 10.5103/KJSB.2010.20.2.167
This study aims to quantitatively compare and analyze kinetic variables in the motion of male and female professional golfers to suggest basic scientific materials for golf iron swing. Five male and five female professional golfers participated in this experiment. Ground reaction force and foot pressure were measured during performing 10 swings for each participants using an iron club. The result of the ground reaction force indicates that the force occurs at the left foot toward right(-) direction in the mid-downswing(E3) and impact(E4) events in X-axis, while it occurs at the right foot toward anterior(-) direction in Y-axis for both male and female, showing a big difference between them. Also, in Z-axis, large force occurs at the left foot in most events. The analyzed result on foot pressure indicates that men have the highest pressure and area at the left foot, and women have the highest ones at the right foot in the mid-downswing(E3) and impact(E4) events in the max foot pressure, ground contact area and average pressure. It is considered that there is difference of central movement methods between men and women. Thus, different education and training on golf swing should be necessary by gender due to their different patterns of golf iron swing.
Effect of Sports Taping on Impact Forces and Muscle Tuning during Drop Landing
Kang, Nyeon-Ju ; Chae, Woen-Sik ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 175~182
DOI : 10.5103/KJSB.2010.20.2.175
The purpose of this study was to evaluate the biomechanical effect of sports taping on the lower limb during drop landing. Twelve male university students who have no musculoskeletal disorder were recruited as the subjects. Principal strain, median frequency, vertical GRF, loading rate, angular velocity and resultant joint moment were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between taped and untaped conditions(p<.05). The results showed that principal strain of the thigh and the shank in taping group were significantly less than those found in control group. These indicated that sports taping may prevent excessive mechanical strain caused by impact force during the deceleration phase. Flexion(-)-extension(+) and varus(-)-valgus(+) resultant joint moment of the knee joint in taping group were greater than corresponding value for control group. It seems that extensor muscle of the knee joint were not only supported by sports taping during knee flexion but also sports taping is effective for minimizing the possibility of injury.
Unilateral Performance Comparison for Taekwondo Kicks between Dominant Leg and Non-Dominant Leg
Kim, Young-Kwan ; Kim, Yoon-Hyuk ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 183~189
DOI : 10.5103/KJSB.2010.20.2.183
The balanced performance of dominant and non-dominant leg is very important to Taekwondo sparring. The purpose of this study was to investigate whether elite Taekwondo athletes would have balanced biomechanical performance and intra-limb coordination in executing different types of Taekwondo kicks. Twelve athletes(more than 10 year practice experience) participated in this study and performed six basic kicks(i.e., the front, roundhouse, side, back, thrashing, and turning-back kick). Results indicated no statistical difference on response time, peak kicking velocity, single limb vertical jump height, and angle-angle plot between dominant leg and non-dominant leg(p>.05). In conclusion, elite Taekwondo athletes had equivalent ability between dominant leg and non-dominant leg in performing Taekwondo kicks. This might be an advantage to elite athletes for Taekwondo sparring because they could use both leg without any restriction.
Changes in Acceleration at the Upper Thigh and Ankle with Variations in Gait Speed and Walkway Slope
Kwon, Yu-Ri ; Kim, Ji-Won ; Kang, Dong-Won ; Tack, Gye-Rae ; Eom, Gwang-Moon ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 191~196
DOI : 10.5103/KJSB.2010.20.2.191
The purpose of this study was to investigate the effect of gait speed and walkway slope on the body acceleration, for the future validation of using an accelerometer in the estimation of energy consumption. Ten young healthy subjects with accelerometers on the upper thigh and ankle walked on a treadmill at 9 conditions(three speeds
three slopes) for 5 minutes. Acceleration signals of four directions, i.e. anterior-posterior(AP), medio-lateral(ML), superior-inferior(SI) and vector sum(VS) directions, of each sensor were measured, and root means squared(RMS) values of them were used as analysis variables. As statistical analysis, repeated measure two-way ANOVA was performed for RMS accelerations at each attachment sites, with slope and velocity as independent factors. At both the upper thigh and ankle, RMS acceleration of all directions were affected by gait velocities(p<.001) showing greater accelerations for higher velocities. Contrary to expectations, no slope effect existed in RMS accelerations at hip. Moreover, RMS acceleraion at ankle decreased with slope in SI and VS directions(p<.01). These results suggests that RMS acceleration cannot reflect the change in physical activity due to the change in walkway slope.
The Effect of Thoracic Posture on The Shoulder Range of Motion and on Three-Dimensional Scapular Kinematics
Park, Seung-Kyu ; Han, Song-E ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 197~204
DOI : 10.5103/KJSB.2010.20.2.197
Scapular position and motion are essential for normal upper limb mobility; Further, the posture of patients with thoracic kyphosis is related to shoulder girdle function and disorder. The purpose of this study was to examine the effects of thoracic posture on the shoulder range of motion and on three-dimensional scapular kinematics. Thirty healthy subjects performed right-arm abduction along the frontal plane while standing in both erect and in slouched trunk posture. The scapular position and rotation, and shoulder and thoracic angles were recorded using a motion analysis system. The scapular upward rotation and internal rotation were significantly altered according to postural tatiges; however, scapular tilt was not affected. Shoulder angle was significantly decreased in the slouched posture as c rpared to tatt in the erect posture. Thus, a slouched posture(thoracic kyphosis) significantly affects the shoulder range of motion and scapular kinematics during shoulder abduction in the frontal plane.
The Comparative Analysis of Visual Perceptual Function and Impulse on Players Chagi in Taekwondo Events
Lee, Young-Rim ; Ha, Chul-Soo ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 205~212
DOI : 10.5103/KJSB.2010.20.2.205
The purpose of this study was to compare the efficiency of visual perception and impulse according to the three types of Taekwondo players to be able to supply an efficient training method, for this a total of 12 representative Taekwondo players of the Korean National team, 4 poomsae players, 4 kyokpa players and 4 kyorugi players weighting between 68 to 74 kg, and the results from the motion analysis system, eye tracker and Electronic hogu are as follows. For the visual perceptual function, the total body reaction time was slowest for the kyokpa group, and for the visible reaction and vision fixation time was longest of the poomsae group, while the performance movement was fastest for the kyorugi group. As for description of the two kicking motions dollyo chagi and dolgae chagi the longer visual fixation helps the accuracy of the kick. In conclusion, as there was a difference between the groups, this information could help to train the visual perception of players according to what event they are participating in.
A Method for Analyzing and Evaluating the Golf Swing Using the Force Platform Data
Sung, Rak-Joon ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 213~219
DOI : 10.5103/KJSB.2010.20.2.213
The purpose of this study is developing a method to analyze and evaluate a golf swing motion using the ground reaction force (GRF) data. Proper weight shifting is essential for a successful shot in golf swing and this could be evaluated by means of the forces between the feet and ground. GRF during the swing were measured from 15 low-handicapped male golfers including professionals. Four clubs(driver, iron 3, iron 5, and iron 7) were selected to analyze the differences due to different characteristics of club. Swings of each subject were taken using a high speed video camera and GRF data were taken simultaneously by two AMTI force platforms. To simplify the GRF data, forces of the three major component of GRF(vertical, lateral, anterior-posterior force) at 10 predefined temporal events for each trial were selected and the mean of each event were calculated and evaluated. Analyzed vertical GRF (VGRF) data could be divided into two different styles, one-legged and two legged. One-legged style shows good weight transfer to the target leg and most of the previous study shows this style as a typical pattern of good players. Therefore the data from the iron 5 swing obtained from 10 one-legged style golfers are provided as criteria for the evaluation of a swing.
Biomechanical Analysis of Trail Running Shoes Applied to Korean Shoe-Lasts
Park, Seung-Bum ; Lee, Kyung-Deuk ; Kim, Dae-Woong ; Yoo, Jung-Hyeon ; Kim, Kyung-Hun ; An, Chang-Shin ; Lee, Tae-Yong ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 221~230
DOI : 10.5103/KJSB.2010.20.2.221
The purpose of this study was to analyze biomechanical factors of trail running shoes applied to korean shoe-lasts. 10 healthy male subjects with an average age of 37.2 years(SD
Development of a Program That Computes the Position of the Club Face Based on the Experimental Data
Park, Jin ; Shin, Ki-Hoon ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 231~237
DOI : 10.5103/KJSB.2010.20.2.231
The moving trajectory of a golf ball is mainly determined by the angles of the clubface and the trajectory of the club shaft. This paper presents a computer program for analyzing the position and angles of the club while the club moves in a circular motion. For this purpose, a mathematical algorithm was developed and implemented on the experimental data(5 m and 10 m carries) using VC++ and OpenGL. A skilled female golfer(174 cm, 65 kg, 0 handicap) was participated in data collection for the short approach shots. An iron club(Titleist 52 degree, 91.5 cm length, 450 g mass), attached with five reflective markers(12 mm), was used to collect experimental data. However, exact 3D coordinates and angles of the clubface are not directly calculated from measured data. A reverse engineering platform(Minolta Vivid910 hardware and Rapidform software) was thus employed to acquire the scanned data of the clubface. The scanned data and measured data were first aligned by applying appropriate coordinate transformations, and then exact coordinates and angles of clubface could be obtained at each position during circular motion. The program(Club Motion Analysis 1.0) exports the open, heel, loft angles of the club.
Development of a Golf Putting Result Recording System Using USB Camera
Kim, Hyung-Sik ; Choi, Jin-Seung ; Tack, Gye-Rae ; Lim, Young-Tae ; Yi, Jeong-Han ;
Korean Journal of Sport Biomechanics, volume 20, issue 2, 2010, Pages 239~243
DOI : 10.5103/KJSB.2010.20.2.239
The putting stroke accounts for 40~50% of total stroke for a golf rounding and most golfers have difficulties on the puting. Studies for the putting stroke have been conducted by analyzing various factors such as kinematics, kinetics, psychologic and physiologic parameters. A lot of devices were developed to support the studies. However there was no appropriate method to measure the position of the ball quantitatively. In this study, we developed a new measurement system to measure and evaluate the putting result. The developed system uses a USB camera to take the 2-dimensional image of the surface including the hole cup at the center of the image and the ball. The position of the ball is extracted as a set of distance and angle in polar coordinate system. We evaluated the new system with an indoor set-up for putting experiments and the system provided accurate measurement results. The proposed system can be combined with the other measurement systems such as 3D motion capture system and force plate without any restriction.