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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 :
Volume & Issues
Volume 23, Issue 4 - Dec 2013
Volume 23, Issue 3 - Sep 2013
Volume 23, Issue 2 - Jun 2013
Volume 23, Issue 1 - Mar 2013
Selecting the target year
Comparative Analyses on Kinematic Variables of Women's Pole Vault Competition at IAAF World Championships Daegu 2011
Choi, Kyoo-Jeong ; Yi, Kyung-Ok ; Kim, Nam-Hee ; Kang, Ji-Eun ; Kim, Hye-Lim ; Moon, Je-Heon ; Jung, Bum-Chul ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 189~200
DOI : 10.5103/KJSB.2013.23.3.189
The purpose of this study was to compare the kinematic analyses of the women's pole vault skills difference between skilled group (1st to 8th place) and less skilled group (10th to 15th place) who participated in IAAF World Championships Daegu 2011. To achieve this goal, 16 women's pole vault player's kinematic analyses was conducted. Player's best performance was recorded by five normal video cameras operating at 60 Hz. The results of this study through the research procedures above are as follows. First, Skilled group's average step length and the ratio of step length to her height were longer than less skilled's group in run-up phase. Second, Skilled group's horizontal velocity was faster than less Skilled group's results. And pole plant angle was lower than less Skilled group's results in take-off phase. Third, Maximum pole flexion angle did not show difference of between two groups in pole bending phase. However, Skilled group's vertical velocity was higher than less skilled group's results.
The Kinematic Analysis of Upper Extremities for Badminton Smash and Drop Motions depends on the Player's Level
Jo, A-Ra ; Yoo, Si-Hyun ; Yoon, Suk-Hoon ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 201~208
DOI : 10.5103/KJSB.2013.23.3.201
The aim of this study was to investigate badminton smash and drop motion depends on player's level. To perform this study, ten male badminton players were participated: five skilled players (SG, age:
cm, body mass:
yrs) and five less-skilled players (LSG, age:
cm, body mass:
yrs). Three-dimensional motion analysis with 7 infrared cameras was performed with a sampling frequency as 200 Hz. Player's swing motion was divided into four events: starting motion (E1), backswing (E2), impact (E3), following (E4). For all upper joints, LSG showed greater angle differences between drop and smash motions than that of SG at E3 (p<.05). For all upper joints, greater angular velocities were found in SG than that of LSG. For both groups, significantly smaller angular velocities were found in drop motion than that of smash motion (p<.05). The greater sequential angular velocities (proximal to distal) were found in SG than LSG during smash motion. Based on our findings, performing the same motion between drop and smash would be related to enhance performance at badminton competition. It is expected that these results will be useful in developing a training program for enhancing performance of badminton athletes.
A Kinetics Analysis of Forward 1
Somersault on the Platform Diving
Jeon, Kyoung-Kyu ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 209~218
DOI : 10.5103/KJSB.2013.23.3.209
This study was to perform the kinetic analysis of forward
somersault on the platform diving. Six men's diving players of the Korea national reserve athletes participated in this study. The variables were analyzed response time, velocity, center of mass (COM), angle, center of pressure (COP) and ground reaction force (GRF) of motion. For measure and analysis of this study, used to synchronized to 4 camcorder and 1 force plate, used to the Kwon3D XP (Ver. 4.0, Visol, Korea) and Kwon GRF (Ver. 2.0, Visol, Korea) for analyzed of variables. The results were as follows; Time factor were observed in maximum knee flexion depending on the extent of use at phase 1 of take-off to execute the somersault. This enabled the subject to secure the highest possible body position in space at the moment of jumping to execute the somersault and prepare for the entry into the water with more ease. Regarding the displacement of COM, all subjects showed rightward movement in the lateral displacement during technical execution. Changes in forward and downward movements were observed in the horizontal and vertical displacements, respectively. In terms of angular shift, the shoulder joint angle tended to decrease on average, and the elbow joints showed gradually increasing angles. This finding can be explained by the shift of the coordinate points of body segments around the rotational axis in order to execute the half-bending movement that can be implemented by pulling the lower limb segments toward the trunk using the upper limb segments. The hip joint angles gradually decreased; this accelerated the rotational movement by narrowing the distance to the trunk. Movement-specific shifts in the COP occurred in the front of and vertical directions. Regarding the changes in GRF, which is influenced by the strong compressive load exerted by the supporting feet, efficient aerial movements were executed through a vertical jump, with no energy lost to the lateral GRF.
Effects of Gymnasts Shoes on Risk Factors of Anterior Cruciate Ligament Injuries during Drop Landing in Female Gymnasts
Lim, Bee-Oh ; Ryu, Young ; Kim, Kew-Wan ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 219~223
DOI : 10.5103/KJSB.2013.23.3.219
The purpose of the study was to investigate the effects of gymnasts shoes on risk factors of anterior cruciate ligament injuries during drop-landing followed by vertical jump in female gymnasts. Thirteen female gymnasts were recruited and performed randomly drop-landing followed by vertical jump in height of her knee with and without shoes. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. Data were analyzed with paired samples t-test with Bonferroni correction. Female gymnasts with shoes showed more reduced thigh maximum adduction angle, and knee maximum extension moment than without shoes. Female gymnasts with shoes showed more increased shank maximum abduction angle than without shoes. In conclusion, Female gymnasts with shoes reduced anterior cruciate ligament injuries risk factors.
Effect of a Prolonged-run-induced Fatigue on the Ground Reaction Force Components
Ryu, Ji-Seon ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 225~233
DOI : 10.5103/KJSB.2013.23.3.225
The purpose of this study was to estimate the potential injury via analyzing ground reaction force components that were resulted from a prolonged-run-induced fatigue. For the present study, passive and active components of the vertical ground reaction force were determined from time and frequency domain. Shear components of GRF also were calculated from time and frequency domain. Twenty subjects with rear foot contact aged 20 to 30, no experience in injuries of the extremities, were requested to run on the instrumented tread-mill for 160 minutes at their preference running speed. GRF signals for 10 strides were collected at 5, 35, 65, 95, 125, and 155 minute during running. In conclusions, there were no significant difference in the magnitude of passive force, impact load rate, frequency of the passive and active components in vertical GRF between running times except the magnitude of active force (p<.05). The magnitude of active force was significantly decreased after 125 minute run. The magnitude of maximum peak and maximum frequency of the mediolateral GRF at heel strike and toe-off have not been changed with increasing running time. The time up to the maximum peak of the anteroposterior at heel-strike moment tend to decrease (p<.05), but the maximum peak and frequency of that at heel and toe-off moment didn't depend significantly on running time.
A Biomechanical Analysis According to Passage of Rehabilitation Training Program of ACL Patients
Jin, Young-Wan ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 235~243
DOI : 10.5103/KJSB.2013.23.3.235
The purpose of this study was to analyse scientific according to period of rehabilitation training of ACL patients. ACL patients seven subjects participated in this study. Gait (1.58 m/sec) analysis was performed by using a 3-D Cinematography, a Zebris system and a electromyograph system. The data were analyzed by paired t-test. The joint angles were recorded from the ankle, knee, hip joints. Peak max dorsi-flexion and peak max plantar-flexion identified significant differences (p<0.05). Another angles were no significant difference. Vertical force (Fz) and max pressure variables improved 6 month RTP better than 3 month RTP. EMG were collected from 4 muscles (rectus femoris, biceps femoris, gastrocnemius, tibialis anterior) with surface electrides in gait system. EMG signals were rectified and smoothed data. EMG signas were no significant difference but they also improved 6 month RTP better than 3 month RTP. More research is necessary to determine exactly what constitutes optimal rehabilitation training period for ACL patients.
Biomechanical Analysis of the Effect that Various Loads has on the Lower Limbs while Descending Stairs
Moon, Je-Heon ; Chun, Young-Jin ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 245~252
DOI : 10.5103/KJSB.2013.23.3.245
The purpose of this study was to analyze the effect that various loads have on the lower limb biomechanics. The following variables were measured and analyzed; performance time for each phase, lower limb moments and joint angles, and ground reaction forces. The kinematic and kinetic data was recorded by 2 force platforms and a motion capture system while 12 healthy adults in their twenties stepped down three steps under loads of 0%, 10%, 20% BW. Results are as follows. First, the different loading conditions did not seem to significantly affect the performance times and the joint angles. Second, the largest ground reaction forces were observed at the 1 step at the 10% BW condition. Finally, at the 0% BW loading condition the right hip extension moment was the smallest and the left hip flexion moment was the largest. The results show that there are not any significant changes in the biomechanics of the lower limbs under loading conditions up to 20% BW. Further investigations including more loading conditions with more weights and more additional steps analyzed are needed.
The Comparison of Symmetry of Vertical Ground Reaction Force on Pattern of Sit to Stand in the Chronic Stroke Patients
Shin, Hwa-Kyung ; Jung, Jin-Woo ; Kim, Youn-Joung ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 253~259
DOI : 10.5103/KJSB.2013.23.3.253
The purpose of this study is to evaluate the influence of posture elements on symmetrical weight bearing during STS (sit-to-stand) in patients with chronic stroke. The subjects were patients diagnosed with stroke: a total of 24 patients (16 males and 8 females) participated in this study. All the participants performed STS tasks(3 foot postures and 2 arm postures). Two force plates (AMTI) were used to measure the peak vertical ground reaction force(Peak Fz) and the symmetrical ratio to peak vertical ground reaction force. The data were analyzed using independent t-test and 2-way repeated analysis of variance. The results of this study were as follows: 1) The peak Fz placed more weight on the paretic leg during STS and 2) The symmetrical ratio to the peak Fz showed a significant difference according to the foot and arm posture (p<.05), and had the highest AYM_GA (
). These results indicate that arm and leg postures during STS in patients with chronic stroke had the highest AYM_GA. We believe that the outcome of this study will be a reference for the prognosis of STS in patients with stroke.
Utilization of Sport Biomechanics for the Correct Posture Exercise Program (Centering in Female Middle School Students)
Kim, Eui-Suk ; Yang, Jeong-Ok ; Lee, Joong-Sook ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 261~269
DOI : 10.5103/KJSB.2013.23.3.261
The purpose of this study was to investigate the degree of improvement of scoliosis, muscle function and VAS between the exercise group and the control group after conducting correct posture exercise program with 20 female students diagnosed with scoliosis through PAPS in M middle school for 12 weeks. The conclusion was as follows. Cobb's angle in exercise group was changed from
which was statistically significant difference (p<.001). However, the change in Cobb's angle was not significant in control group, hence there was no statistically significant difference. The limber back strength was changed from
kg and sit-up was changed from
times in exercise group, but they were not statistically significant. Control group also showed no statistically significant change in back strength and sit-up. The degree of VAS was changed from
which was a statistically significant difference (p<.01) in exercise group. However, there was no statistically significant difference in control group. Consequently, correct posture exercise program was considered to be effective for the reduction of Cobb's angle and degree of VAS for middle school female students with scoliosis. Therefore the correct posture exercise program can be recommended for youth scoliosis to improve and prevent the body imbalance and ultimately for the health of the youths.
Effect of Pilates Reformer Training on Gait Improvement of Subjects with Asymmetric Pelvic Rotation
Moon, Ok-Kon ; Han, Song-E ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 271~278
DOI : 10.5103/KJSB.2013.23.3.271
The purpose of this study was to determine the effect of Pilates Reformer training on gait improvement of subjects with asymmetric pelvic rotation. The seven subjects with greater pelvic rotation in right swing were assessed twice, 4 weeks apart, during which there was submitted to a Pilates Reformer training (three 40 min session per week). The kinematic data consisted of pelvic rotation and flexion angle of hip and knee joint was measured during gait. In comparison between both leg swings, max, min and range values of pelvic rotation was not significantly difference. After training, range of pelvic rotation in right swing was significantly decreased, but in left swing was not. In comparison between both leg swings, the values of max of hip and knee joint angle was significantly difference. After training, max values of angle of knee joint in right swing was significantly increased, but in left swing was not. The result of this study revealed that Pilates Reformer training was effective in improving gait to symmetric pelvic rotation.
Effect of Head Posture and Breathing Pattern on Muscle Activities of Sternocleidomastoid and Scalene during Inspiratory Respiration
Koh, Eun-Kyung ; Jung, Do-Young ;
Korean Journal of Sport Biomechanics, volume 23, issue 3, 2013, Pages 279~284
DOI : 10.5103/KJSB.2013.23.3.279
The purpose of this study was to determine the effect of head posture and respiratory pattern on muscle activities of sternocleidomastoid (SCM) and scalene during maximal respiration. The seventeen subjects with upper-costal breathing pattern were participated in this study. Surface electromyography was used to measure the muscles activities of SCM and scalene. The volume and velocity of inspiration were monitored by using the spirometer in each subject. Each subject was performed the 3-cycle of respiration in each condition. The mean values of three peak muscle activity in each muscle were used in the data analysis. A2 (head posture: forward head posture: FHP vs. neutral posture) X 2 (breathing pattern: costal vs. diaphragmatic) repeated-measures analysis of variance (ANOVA) was used to compare the normalized muscle activities of the SCM and scalene. The results showed that the muscle activities of SCM and scalene in diaphragmatic breathing were significantly lower than those in costal breathing for each head posture (p<.0125). The muscle activities of SCM in neutral position were lower than those in forward head position during costal breathing (p<.0125). The diaphragmatic breathing in neutral position of head is recommended to decrease the tension of the accessory inspiratory muscles during respiration in neck-pain patients with FHP.