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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Sport Biomechanics
Journal Basic Information
Journal DOI :
Korean Society of Sport Biomechanics
Editor in Chief :
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
Kinematic Analysis of T-Stop Motion by Inline Skate Rolling Speed
Han, Je-Hee ; Woo, Byung-Hoon ; Kim, Jeong-Goo ; Kim, Tae-Whan ; Kim, Sung-Sup ; Kim, Eui-Hwan ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 355~364
DOI : 10.5103/KJSB.2010.20.4.355
The purpose of this study was to investigate the kinematical analysis of T-stop motion by inline skate rolling speed. Six subjects were participated in the experiment(age:
yrs). The study method adopted 3-dimensional analysis and 2 cameras for filming to analyze the required displacement of center of mass, displacement of right and left hip joint, displacement of right and left knee joint, displacement of trunk tilt using by APAS. The results were as follows; In anterior-posterior displacement of COM, the faster rolling speed, the longer displacement at phase 2. In vertical displacement of COM, the faster rolling speed, the lower displacement. In medial-lateral displacement of COM, there was no significant on rolling speed. In angular displacement of right thigh segment, the faster rolling speed, the bigger displacement in X and Z axis. In angular displacement of left thigh segment, the faster rolling speed, the lower displacement in X axis. In angular displacement of right shank segment, the faster rolling speed, the bigger displacement in Z axis. In angular displacement of left shank segment, the faster rolling speed, the bigger displacement in X and Y axis. In angular displacement of trunk segment, the faster rolling speed, the bigger displacement in Z axis.
Comparative Analysis of Nordic Walking and Normal Gait Based on Efficiency
Kim, Ro-Bin ; Cho, Joon-Haeng ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 365~372
DOI : 10.5103/KJSB.2010.20.4.365
The purpose of this study were to analyze the changes in kinematic and kinetic parameters and to find biomechanical benefits of Nordic Walking and normal gait performed under the same velocity. Nine participants(age:
) was chosen. The velocity of gait was set by 5.75 km/h which was made by a Nordic Walking professional. The data were collected by using VICON with 8 cameras to analyze kinematic variables with 200 Hz and force platform to analyze kinetic variables with 2000 Hz. The results of this study were as follows. First, when compared with Normal gait, Nordic Walking group showed decreased Plantarflexion angle and ROM. Second, Nordic Walking group showed decreased knee flexion angle and ROM. Third, Nordic Walking group showed increased hip joint movement. Fourth, Nordic Walking group showed higher active GRF but decreased loading rate from delayed Peak Vertical GRF time and increased impulse. Fifth, Nordic Walking group showed longer ground contact time. Through this study, we found that Nordic Walking showed higher stability and efficiency during gait than normal gait and that Nordic Walking may help people who have walking difficulties.
The Effect of Training Program for the Balance on the Gait Stability
Lee, Young-Taeck ; Kim, Hoon ; Shin, Hak-Soo ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 373~380
DOI : 10.5103/KJSB.2010.20.4.373
The purpose of this study was to evaluate the effect of balance training on gait stability. The study population included 17 male high school students who were divided into 3 groups, each of which underwent one of the following types of balance-training programs for 8 weeks: 1 foot standing on cushion foam, trunk muscle training, and inverted body position training. 0, 4, and 8 weeks, the following experiment was performed: The participants were asked to close their eyes and take 17 steps; the stability of forward and sideward movement was determined, and the direction linearity was measured. The results revealed that all the training programs caused a decrease in stride deviation and an increase in the and the stride length, thereby improving the stability of forward movement. All the programs decreased the variation in step width and were thus also effective in improving the stability of sideward movement. The inverted body position training program was considered very effective because the cross point appeared on post hoc graphic analysis after 4 weeks, and the deviation length for 10 m was low, i.e., below 4 cm. All the programs were effective with respect to direction linearity because they decreased the deviation in direction widths. The results indicate that whole-body neurocontrol training is more effective than simple muscle training and local focused balance training, although this neurocontrol training-in the form of inverted body position training-required a longer training period than did the other programs.
Changes of Walking Pattern for Young Adults dur ing Level Walking under Low Illumination
Choi, Jin-Seung ; Kang, Dong-Won ; Bang, Yun-Hwan ; Tack, Gye-Rae ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 381~386
DOI : 10.5103/KJSB.2010.20.4.381
This study examined the changes in the walking pattern during level walking under low illumination conditions. Fourteen male subjects (
) with normal vision and no disabilities were enrolled in this study. All experiments were performed on a level walkway with three conditions: normal walking (preferred & low speed) and walking with low illumination. 3D motion capturing system was used for acquisition and analysis of the walking motion data with a sampling frequency of 120Hz. The walking speed, normalized jerk(NJ) at the center of mass(COM), wrist and heel, knee and elbow joint angle, ratio of the knee joint angle to elbow joint angle and the toe clearance on stance phase were used to compare the differences in walking pattern between the two illumination conditions, The results showed that the walking speed and joint angles decreased in low illumination, whereas the NJ and toe minimum clearance increased. In low illumination, most variables were similar to effects of low speed walking, but toe clearance was different from the effects of low speed. These results can be used as primary data for examining the changes in the level walking pattern of young adults under low illumination. Further study will be needed to compare these results in young adults with those in the elderly.
Comparison of Pregnant Women's Mechanical Energy between the Period of Pregnancy and Postpartum
Hah, Chong-Ku ; Yi, Jae-Hoon ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 387~393
DOI : 10.5103/KJSB2010.20.4.387
The purpose of this study was to compare pregnant women's gait parameters and mechanical energies caused by changes in hormone levels and anatomical features such as body mass, body-mass distribution, joint laxity, and musculo-tendinous strength from pregnancy to postpartum. Ten subjects (height:
) participated in the four times experiments (the first, middle, last term and after birth) and walked ten trials at a self-selected pace without shoes. The gait motions were captured with Qualisys system and gait parameters were calculated with Visual-3D. Pregnant women's gait velocities were decreased during the pregnancy periods, but increased after birth. Stride width and cycle time were increased during pregnancy, but decreased after birth. Thigh energy (77.4%) was greater than shank energy (19.06%) or feet (3.54%) about total energy of the lower limbs. Their feet (Left R2=0.881, Right R2=0.852) and shank (Left R2=0.318, Right R2=0.226) energies were significantly increased (positive correlation), but double limb stance time (DLST, R2=0.679) and body total energy (R2=0.138) were decreased (negative correlation) for their velocities. These differences suggest that thigh segment may be a dominant segment among lower limbs, and have something to do with gait velocities. Further studies should investigate joint power and joint work to find energy dissipation or absorption from pregnancy period to postpartum.
Effects of Rehabilitation Duration on Lower Limb Joints Biomechanics dur ing Drop Landing in Athletes with Functional Ankle Instability
Cho, Joon-Haeng ; Kim, Kyoung-Hun ; Lee, Hae-Dong ; Lee, Sung-Cheol ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 395~406
DOI : 10.5103/KJSB.2010.20.4.395
The purpose of this study was to analyze the changes in kinematic and kinetic parameters of lower extremity joint according to rehabilitation period. Fourteen collegiate male athletes(age:
) and fourteen collegiate athletes on functional ankle instability(age:
) with the right leg as dominant were chosen. The subjects performed drop landing. The date were collected by using VICON with 8 camera to analyze kinematic variables and force platform to analyze kinetic variables. There are two approaches of this study, one is to compare between groups, the other is to find changes of lower extremity joint after rehabilitation. In comparison to the control group, FAI group showed more increased PF & Inversion at IC and decreased full ROM when drop landing. Regarding the peak force and loading rate, it resulted in higher PVGRF and loading. FAI group used more increased knee and hip ROM because of decreased ankle ROM to absorb the shock. And it used sagittal movement to stabilize. In terms of rehabilitation period, FAI group showed that landing patterns were changed and it increased total ankle excursion and used all lower extremity joint close to normal ankle. Regarding the peak force and loading rate, FAI group decreased PVGRF and loading rate. and also showed shock absorption using increased ankle movement. And COP variable showed that proprioception training increased stability during 8 weeks. The results of this study suggest that 8 weeks rehabilitation period is worthwhile to be considered as a way to improve neuromuscular control and to prevent sports injuries.
The Effect of Spor ts Taping on Lower Extremity Muscles in Ver tical Jump
Lee, Jong-Hun ; Lee, Young-Sik ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 407~414
DOI : 10.5103/KJSB.2010.20.4.407
The purpose of this study was to evaluate the effect of taping-tape with or without using spiral taping on vertical jump. The subjects for this study were about 20 years old healthy male college students without muscloskeletal diseases. Data for EMG activity and Ground Reaction Force(GRF) were estimated at three knee angles(i.e., 45, 90 & full degree). As a result, there was no statistical significance in max GRF at 90 and full degree regardless of spiral taping-tape. On the other hand, statistical significance was found when vertically jumping at 45 degree knee angle(p<.05). All the data for EMG activity at the three knee angles were not statistically significant, but there was a trend for a decrease in average EMG activity in elector spinae & Medial gastrocnemius at 90 degree knee angle. Based on these data, initial flexor action of knee was stabilized with spiral taping-tape when vertically jumping, resulting in improved muscular activity in Medial gastrocnemius. In conclusion, taping technique for jumping ability associated muscles like quadriceps is also required to develop.
Comparisons of Abdominal Muscles Thickness During Single Leg Holding Exercise on Stable Surface and on a Foam Roller Using Ultrasound Imaging
Jung, Do-Young ; Koh, Eun-Kyung ; Kim, Su-Jeong ; Kwon, Oh-Yun ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 415~420
DOI : 10.5103/KJSB.2010.20.4.415
The purpose of this study was to compare the thickness of the abdominal muscles during single leg holding exercise (SLH) in a hooked lying position on stable surface and on a foam roller. Healthy twenty subjects who had no medical history of lower extremity or lower back pain were recruited for this study. Muscle thickness of transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) was recorded using real-time ultrasonography during SLH. Paired t-test with Bonferroni adjustment was used to compare the muscles thickness during SLH on stable surface and on a foam roller. The result showed that TrA and IO muscle demonstrated greater thickness during SLH on foam roller than those on the stable surface. This finding suggests that SLH on an unstable foam roller is more effective to increase thicknesses of TrA and IO muscles than stable surface.
Relationship between the Biomechanical Analysis and the Qualitative Analysis of Video Software for the Walking Movement
Bae, Young-Sang ; Woo, Oh-Goo ; Lee, Jeong-Min ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 421~427
DOI : 10.5103/KJSB.2010.20.4.421
The purpose of this study was to investigate the relationship between the quantitative analysis of biomechanical movement and the qualitative analysis of video software in order to evaluate for the walking movement. The fourteen collegiate students who agreed with the purpose and method of this study participated as subjects. The slow walking and fast walking of the subjects in the place of experiment were photographed, and calculated several mechanical factors. This empirical evidence from the experiment indicated the significant difference(p<.001) between each distant factors of the walking movement for both analyses methods, but there was no statistically significant difference between the spacial factors observed in the experiment. For more detail, no significant difference between the walking ratios that expressed the coordination between stride length and stride frequency was found. The findings also indicated the high coefficient of correlation(over r=.9) which supports higher explanation force for the biomechanical method and the Dartfish video software method. Therefore, if the data was gathered by using the proper experimental method, the video software method could be used just like the quantitative data of biomechanical method.
Kinematic Skill Analysis of the Turn Motion and Release Phase in Female Hammer Throw
Chung, Nam-Ju ; Kim, Jae-Pil ; Song, Ok-Heung ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 429~436
DOI : 10.5103/KJSB.2010.20.4.429
The purpose of this study was to analyze the kinematic factors and throwing variables for the 3-turn and 4-turn techniques and for release as well as to provide technical advice for improving athletic performance in hammer throwing. Data analysis led to the following conclusions: To increase the rotation speed for the 3-turn and 4-turn techniques, the time elapsed during the 1-foot support period should be decreased the distance between the rotating foot and the rotation axis should be small and the height of the hip joint should be increased at the times of release The throwing angle at the moment of release should be more than 40 degrees, and the throwing position should be taken vertically high at the shoulder joints. To accelerate the motion of the hammer, the speed should not be reduced during the 1-foot support period but should be increased during the 2-foot support period for much greater acceleration. In the 3-turn technique, the angles of the shoulder axis and hummer string should be dragged angle at the maximum point and lead angle at the minimum point, and dragged angle at the maximum and minimum points in the 4-turn at the time of relase The upper body should be quickly bent backward, the knee angle should be extended, and the angles of the shoulder axis and hammer string should be dragged angle close to 90 degrees.
Comparison of Selected Joint Angles at Golf Address Among Three Different Somatotypes
Choi, Min-Chul ; Lee, Chang-Jin ; Lim, Young-Tae ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 437~445
DOI : 10.5103/KJSB.2010.20.4.437
This study was aimed at comparing selected joint angles at the golf address stance by categorizing three different body types. 43 elite male golfers were selected and 9 of them turned out to be the ectoderm while 24 of them to be the mesoderm. The remaining 10 subjects were the endoderm. The measurement was carried out at the address stance with the number 7 iron and the driver. The result showed that the angle of trunk flexion did not different among body types. The trunk tilting angle became more inclined to the right side, which confirmed the guidelines from most of golf lesson books, for bigger people since they tended to put more weight on the right foot. The angle of both knees showed similar but the right knee was bent more than the left knee. The target direction and body alignment faced more to the left side than the target spot because of the influence of open stance and natural aiming position. It seems that pelvis and knees turned a little bit more to the right side than the target direction in order to maintain the parallel. Overall, significant differences among body types were found at the trunk tilting angle and pelvis-target alignment and golf address configuration can be differentiate by these factors.
Kinematic Analysis of Secondary School Golf Player's Putting Stroke Motion
Ko, Jae-Yeon ; Oh, Cheong-Hwan ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 447~455
DOI : 10.5103/KJSB.2010.20.4.447
The objective of this study was to analyze the difference in kinematic variables for successful and unsuccessful golf putting strokes. The study population included 8 male secondary school golf players who had played golf for over 3 years and whose handicap was 4 or lower. A hole was made on a 5-m-long artificial flat mat for practice, and an environment similar to that of a real green was created. The participants' motions were analyzed through 3D image analysis, and the difference in kinematic variables for successful and unsuccessful putting strokes in the same direction was determined. Data analysis revealed the following findings: The time spent for a segment of putting was the greatest for the backswing segment for both successful and unsuccessful strokes. During address and impact, the both changed to a larger extent. For successful putting strokes, the change in the elbow angle during the downswing was greater for the right elbow than for the left elbow. For both successful and unsuccessful putting strokes, the left shoulder angle increased during the segment from address to the turning point and decreased during the segment from the turning point to impact. In contrast, the right shoulder angle significantly differed between successful and unsuccessful putting strokes only during address. During successful and unsuccessful motions, the swing was executed with the moving displacement of the X-axis of the club head maintained almost constant along a straight light without back and forth movement. In the backswing segment, moving displacement of the Y- and Z-axes was greater in successful strokes than in unsuccessful strokes; however, this difference was very small for the Y-axis. The velocity of the club head for successful and unsuccessful motions significantly differed during address and at the turning point. The highest velocity of the ball was greater for successful than for unsuccessful putting strokes.
Kinematical Analysis of Projection Factors to Record Difference dur ing Women's Javelin Throwing
Park, Jae-Myoung ; Yoon, Seok-Hoon ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 457~467
DOI : 10.5103/KJSB.2010.20.4.457
This study intends to analyze the projection factors' difference on each record of women's javelin throwing. For this purpose, the research analyzed the best record and the lowest one of athletes in top 1~7 ranks respectively, who participated in 2009 Daegu Pre-Championship Meeting. For analyze kinematic factors, we analyzed their game photos mainly shot by 3 cameras installed in side places. The used analysis program was Kwon3D 3.1. Analysis variables were the projection velocity, angle, height, trunk lean angle, and supporting leg's knee angle. The results concluded as follows: Different record showed statistically significant differences(p<.05) in terms of horizontal velocity and resultant velocity. There were no statistically significant differences in the variables of projection angle, its height, trunk lean angle and knee angle of support leg. But for the analyzed results to each individual characteristics, the horizontal velocity, projection height, knee angle of support leg and trunk lean angle of release event appeared to have influence on record.
Evaluation of Insole-equipped Ankle Foot Or thosis for Effect on Gait based on Biomechanical Analysis
Jung, Ji-Yong ; Kim, Jin-Ho ; Kim, Kyung ; Trieu, Pham Hai ; Won, Yong-Gwan ; Kwon, Dae-Kyu ; Kim, Jung-Ja ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 469~477
DOI : 10.5103/KJSB.2010.20.4.469
The purpose of this study was to evaluate the effects of insole-equipped ankle-foot-orthoses (AFO) on gait. 10 healthy males who had no history of injury in the lower extremity participated in this study as the subjects. The foot of each subject was first scanned, and the insole fit to the plantar was made using BDI-PCO(Pedcad Gmbh, Germany). The subject then was made to walk on a treadmill under four experimental conditions: 1) normal walking, 2) walking wearing AFO, 3) walking wearing AFO equipped with the insole, 4) walking wearing pneumatic-ankle-foot-orthosis (pAFO) equipped with the insole. During walking, foot pressure data such as maximum force, contacting area, peak pressure, and mean pressure was collected using Pedar-X system (Novel Gmbh, Germany) and EMG activity of lower limb muscles such as gastrocnemius medial head, gastrocnemius lateral head, and soleus was recorded using MP150 EMG module (BIOPAC System Inc., USA). Collected data was then analyzed using paired t-test in order to investigate the effects of the insole. As a result of the analysis, when insole was equipped, overall contacting area was increased while both the highest peak pressure and the mean pressure were significantly decreased, and EMG activity of the lower limb muscles was decreased. On the contrary, the cases of wearing AFO showed the decreased contacting area and the increased pressures. Therefore, the AFO equipped with a proper insole fit well to the foot can help comfortable walking by spreading the pressure over the entire plantar.
Effects of High-heeled Shoe with Different Height on the Balance during Standing and Walking
Ryu, Ji-Seon ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 479~486
DOI : 10.5103/KJSB.2010.20.4.479
The purpose of this study was to determine the effects of high-heeled shoe on the quiet standing and gait balance. Twenty women (mean height:
, mean body mass:
, mean age:
yrs..) who were without history or complain of lower limb pain took part in this study. They were asked to stand quietly on a force platform for 30 sec and walk on it at their preferred walking speed (mean speed
.) with wearing three different high-heeled shoe, 3, 7, 9 cm high for collecting data. Data were randomly recorded to collect two trials for quiet standing and five trials for walking The parameters to have been analyzed for comparison between three conditions of the height of high-heeled shoe were COP(Center of Pressure) range, COP velocity, sway area, and free moment on the static balance and COP range, COP velocity, and free moment on the dynamic balance. In this study, high-heel height affected on the COP range and velocity in the ante-posterior direction during walking, dynamic balance, but didn't affect on the quiet standing, static balance.
A Comparative Analysis of X-factor Stretch between Driver and Iron Swing in Male Professional Golfers
Park, Tae-Jin ; Seo, Kook-Eun ;
Korean Journal of Sport Biomechanics, volume 20, issue 4, 2010, Pages 487~495
DOI : 10.5103/KJSB.2010.20.4.487
The purpose of this study was conducted to make a comparative biomechanical analysis of X-factor and X-factor stretch during driver and iron swing. The subjects were composed of 10 professional golfers with more than 10 years career. The result was as follows: First, the analysis of the back swing with driver and iron swing showed no differences statistically between both the timing in horizontal rotating of shoulder and hip, the time required for X-factor stretch also showed no differences statistically. Second, the back swing with a driver swing showed more maximum horizontal rotation of shoulder and hip joint than the back swing with an iron swing, but the twist of shoulder and hip that was X-factor stretch angle showed no difference. Third, the GRF of the max value for the left and right foot during shoulder and hip horizontal rotation of back swing showed no differences statistically in the movement of driver and iron swing during the back swing, and the GRF of X-factor stretch for the left and right foot showed no differences statistically in driver and iron swing. Therefore the result of this research showed that the operation of torso(X-factor stretch) and weight shifting were similar although the horizontal rotation of body was different during the driver and iron swing.