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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 18, Issue 4 - Dec 2008
Volume 18, Issue 3 - Sep 2008
Volume 18, Issue 2 - Jun 2008
Volume 18, Issue 1 - Mar 2008
Selecting the target year
The Study of Plantar Foot Pressure Distribution during Obstacle Crossing with Different Height in Normal Young Adults
Han, Jin-Tae ; Lee, Myung-Hee ; Kim, Kyoung ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 1~9
DOI : 10.5103/KJSB.2008.18.2.001
The purpose of this study was to investigate the effect of different obstacle heights on the plantar foot pressure during obstacle crossing. Sixteen healthy adults who had no musculoskeletal disorders were instructed to perform unobstructed level walking and to step over obstacles corto 10cm, 20cm, 30cm. Plantar foot forces and pressures were recorded by the Footmat system(Tekscan, Boston, USA) during level and obstacle walking with barefoot. Plantar foot surface was defined as seven regions for pressure measurement; two toe regions, three forefoot regions, one midfoot region, one heel region. One-way ANOVA was used to compare each region data of foot according to various heights. The results indicated that there are significant differences on peak pressure and maximal forces regarding each region at stance phase. As height of obstacle became high, the pathway of COP had a tendency to be short and abducted. Plantar pressure of foot could be changed by obstacle height and these findings demonstrated that obstacle with different height have an effect on structure and function of the foot.
The Effects of Obstacle Height on the Stepping Over Gait in Parkinson's Patients
Kim, Mi-Young ; Lim, Bee-Oh ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 11~17
DOI : 10.5103/KJSB.2008.18.2.011
Falls associated with tripping over an obstacle can be dangerous, yet little is known about the strategies used for stepping over obstacles by Parkinson's patients. The purpose of this study was to investigate stepping over gait characteristics according to obstacle height in Parkinson's patients. The gait of 7 Parkinson's patients was examined during a 5.0 m approach to, and while stepping over, obstacles of 0, 2.5, 5.2, and 15.2 cm. Only five Parkinson's patients were able to clear all obstacles successfully; as such, only their data were analyzed. A one-way ANOVA for repeated measures was employed for selected kinematic variables to analyze the differences of the height of four obstacles. The results showed significant differences between obstacle height and: approaching speed (AS), foot clearance from the obstacle(FC), and step width (SW). The results showed no significant differences between obstacle height and: crossing speed (CS), toe distance (TD), and heel distance (HD). This strategy tends to reduce the risk of toe contact with the obstacle. Parkinson's patients were stepping over the obstacle slowly, stably and inefficiently.
Assessment of Single-leg Stance Balance Using COP 95% Confidence Ellipse Area
Youm, Chang-Hong ; Park, Young-Hoon ; Seo, Kuk-Woong ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 19~27
DOI : 10.5103/KJSB.2008.18.2.019
The purpose of this study was to investigate of assessment of the ability of balance control using COP 95% confidence ellipse area while executing single-leg stance with eyes open and eyes closed through GRF system. The subjects participated in this study were 7 female yoga group and 7 female control group. The yoga training affected to improve the ability of balance control because the yoga group's COP AP and ML standard deviation and COP 95% confidence ellipse area were smaller than control group in both a single-leg stance with eyes open and eyes closed. Visual affected to the ability of balance control in a single-leg stance. I consider COP 95% confidence ellipse area as a high variable for determining the ability of balance control, and therefore suggest that additional studies for various groups and subjects will be required in the future.
A Study about the Training Program for the Tippelt Technique on the Parallel Bars
Back, Jin-Ho ; Park, Jong-Chul ; Yoon, Chang-Sun ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 29~39
DOI : 10.5103/KJSB.2008.18.2.029
This study was to provide for Tippelt technique which was a basic technique used in parallel bars. The program was applied to players for 8 weeks. Then it was analyzed by using 3Dmotion Analysis system to seek the difference between before and after using the program. Moreover establish the improvement and trait for newly made program. The program was made up of down-swing, up-swing and composite connection-phase training. Through down-swing training, shoulder angle made extension and chest closed quickly. As a result, players' performance have improved. Through up-swing training, legs kicking to vertical direction and trunk stood up fastly. As a result, players' performance have improved. When going upward, the center of mass must be in control not to have a lot of movement and hip angle extension using the bar is very positive coaching. When coaching composite connection in training from down-swing to up-swing, must have enough air phase time using center of mass vertically to have extension of leg. As a result, players' performance have improved by having increase of air phase time.
A Study of Lower Extremities Joint Moment Pattern by Stance Types in Tennis Serve
Kim, Sung-Sup ; Kim, Eui-Hwan ; Kim, Euy-Jin ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 41~48
DOI : 10.5103/KJSB.2008.18.2.041
The purpose of this study was to analyze the lower extremities joint moment pattern by two types of service motion in tennis pinpoint and platform stance. Seven skilled high school tennis players participated, and the kinematics were recorded by the Vicon motion analysis system. For the gathering and analysis of the data Workstation, Bodybuilder and polygon were used. joint moments and Ground Reaction Forces for the phases involved were analyzed with the following results. There was a different moment pattern for the lower extremities between the two serve motions. For the platform stance there was only a large dorsal flexion moment but for the pinpoint stance there were other large moments. The flexion and maximum moment of the lower extremities occurred at the point of change from back swing and to the forward swing motion. Therefore, this data provides evidence that there is a high risk of injury at this point.
Effects of Walking Speeds and Cognitive Task on Gait Variability
Choi, Jin-Seung ; Kang, Dong-Won ; Tack, Gye-Rae ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 49~58
DOI : 10.5103/KJSB.2008.18.2.049
The purpose of this study was to identify effects of walking speed and a cognitive task during treadmill walking on gait variability. Experiments consisted of 5 different walking speeds(80%, 90%, 100%, 110% and 120% of preferred walking speed) with/without a cognitive task. 3D motion analysis system was used to measure subject's kinematic data. Temporal/spatial variables were selected for this study; stride time, stance time, swing time, step time, double support time, stride length, step length and step width. Two parameters were used to compare stride-to-stride variability with/without cognitive task. One is the coefficient of variance which is used to describe the amount of variability. The other is the detrended fluctuation analysis which is used to infer self-similarity from fluctuation of aspects. Results showed that cognitive task may influence stride-to-stride variability during treadmill walking. Further study is necessary to clarify this result.
A Study on Real-Time Sports Activity Classification & Monitoring Using a Tri-axial Accelerometer
Kang, Dong-Won ; Choi, Jin-Seung ; Tack, Gye-Rae ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 59~64
DOI : 10.5103/KJSB.2008.18.2.059
This study was conducted to study the real-time sports activity classification and monitoring using single waist mounted tri-axial accelerometer. This monitoring system detects events of sports activities such as walking, running, cycling, transitions between movements, resting and emergency event of falls. Accelerometer module was developed small and easily attachable on waist using wireless communication system which does not constrain sports activities. The sensor signal was transferred to PC and each movement pattern was classified using the developed algorithm in real-time environment. To evaluate proposed algorithm, experiment was performed with several sports activities such as walking, running, cycling movement for 100sec each and falls, transition movements(sit to stand, lie to stand, stand to sit, lie to sit, stand to lie and sit to lie) for 20 times each with 5 healthy subjects. The results showed that successful detection rate of the system for all activities was 95.4%. In this study, through sports activity monitoring. it was possible to classify accurate sports activities and to notify emergency event such as falls. For further study, the accurate energy consumption algorithm for each sports activity is under development.
The Effect of Balance Exercise on Postural Control and Shooting Record in Archers
Kim, Jae-Pil ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 65~74
DOI : 10.5103/KJSB.2008.18.2.065
The purpose of this study was to investigate the effect on postural control and shooting record by archers of the balance exercise program for 12-weeks based on sprinter/skater pattern. the subject were 12 female archers(the control group 6, the experimental group 6) and the motion was measured using active balance system. the results were as follows. 1. Static postural controllability of archers was improved to reduce the whole path length and the sway of the COBx, COBy after the balance exercise program for 12-weeks based on sprinter/skater pattern. 2. Dynamic postural controllability of archers was improved to reduce the whole path length after the balance exercise program for 12-weeks based on sprinter/skater pattern. 3. Archers' postural controllability was improved when shooting after 12-week balance exercise program based on sprinter/skater pattern. but not effect shooting record.
Correlation between Lower Extremities Joint Moment and Joint Angle According to the Different Walking Speeds
Shin, Seong-Hyoo ; Lee, Hyo-Keun ; Kwon, Moon-Seok ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 75~83
DOI : 10.5103/KJSB.2008.18.2.075
The purpose of this study was to evaluate the correlation between joint moment and joint position angle according to the different walking speeds. According to the different walking speeds(1.5m/s, 1.8m/s, 2.1m/s), experiments were terminated by 8 male subjects. In conclusion, 1. The peak extensor moment of knee joint increased by increasing walking speed, however, walking speed didn't have an effect on peak flexor and abductor moment of knee joint. 2. The position angle of knee joint increased movement of flexion, but other position angles of knee joint didn't have difference when the peak extensor moment generated. 3. The peak joint moment of hip significantly increased in extension, flexion and abduction by increased walking speed. 4. The hip position angle showed more flexible at the hip peak flexor/extensor moment generated. 5. The co-ordination pattern between peak knee joint moment and knee position angle were mathematically modeled by using a least square method. We could get the high level value of R2. We expect to apply this results for evaluating the physical faculty of knee joint.
Kinematical Analysis of Swing Motion with Golf Iron Clubs Used by Elite Golfers
Kim, Kab-Sun ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 85~94
DOI : 10.5103/KJSB.2008.18.2.085
The purpose of this study is to provide basic materials for amateur golf players or golf maniacs to learn desirable iron swing motions. This study compared and analyzed the swing motions of iron clubs(3, 6, 9) by using 3-D in three elite golf players. 1. There was no a great difference in the total of swing time by club and the time by phase was nearly similar. 2. There was no a difference in the change in a head location at address and impact by club. 3. The angle change in a right knee joint was similar by club except the difference according to the length of the club. 4. There was a subtle difference in hip rotation angle by club. 5. In each club, the same rotation angle of shoulder joint at address and impact motions contributed to accurate swing, and the maintenance of more than
of shoulder rotation angle in top swing increased swing rotation. 6. Although subtle, the forward angle of upper body was increased with a shorter club.
of forward angle of upper body was maintained at address, top swing, and impact motions.
The Process of the Kinematic Coordination and Control of Dollyochagi Motion in Taekwondo
Yoon, Chang-Jin ; Chae, Woen-Sik ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 95~104
DOI : 10.5103/KJSB.2008.18.2.095
The purpose of this study was to investigate kinematic coordination and control of lower segments in skill process. For the investigation, we examined the difference of resultant linear velocity of segments and angle vs angle graph. Novice subjects were 9 male middle school students who has never been experienced a taekwondo and expert subjects were 7 university taekwondo players. We analyzed kinematic variables of Dollyochagi motion through videographical analysis and the conclusion were as follows. 1. Examining the graph of novice subjects' maximal resultant linear velocity of the thigh, shank, and foot segment, as it gets closer to the end of the training, the maximal resultant linear velocity in each segment increased. Statistical analysis showed the following results; thigh segment caused the increase of speed, using the trunk segment's momentum in the latter term of learning, while the shank segment utilized the momentum of the adjacent proximal segment at the beginning of learning, and the foot segment in the middle of learning. 2. Until the point where the knee joint angle is minimum, as the novice group learn the skill, the flexion of knee and hip joints has changed into the form of coordination pattern in phase. On the other hand, the expert group showed continual coordination pattern in phase that the movement sequences were smooth. From the knee joint maximal flexion to impact timing, all novice and expert groups showed coordination pattern out of phase. 3. From the knee joint maximal flexion to impact timing, the ankle joint was fixed and the knee joint was extended to all the novice stages and expert subjects.
A Comparison Analysis of EMG according to Weight Class and Increase Record of Clean and Jerk Techniques Weightlifting in High School Female Weight Lifters
Park, Il-Bong ; Yeo, Nam-Hwoeh ; Kim, Jung-Tae ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 105~114
DOI : 10.5103/KJSB.2008.18.2.105
The purpose of this study was to compare of muscles in clean and jerk techniques between 69kg class(n=3), 58kg class(n=3) in high school female weight lifters using EMG(electromyographic) system. EMG analysis were executed on 6 major muscles and dividing clean and jerk techniques into 6 phases. In that result, in the difference by weight, it was shown that EMG value increased gradually as the weight is raised of all muscles group & phases in 58kg class. In EMG signal scale by classes, it was shown that EMG signal scale didn't increase according to class & weight. In the result of this study, that EMG value was inconsistent in 69kg class is showing that the consideration of the technical factor together with muscle power has positive affect more on the performance improvement in the heavy class.
The Evaluation of Lower Extremity Muscles in Combat shoes Custom Foot Orthotics
Suh, Sung-Hyeok ; Kim, Ro-Bin ; Cho, Young-Jae ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 115~124
DOI : 10.5103/KJSB.2008.18.2.115
The purpose of this study was to examine the effects of customized foot orthotics on lower extremity muscle activity and fatigue during march in combat boots. Four volunteers with normal foot and five volunteers with excessive pronation foot among soldiers on service were fitted with foot orthotics. The electromyography signal from activity of low extremity muscles were collected with surface electromyography device during walking on the treadmill. The walk on the treadmill was performed with a speed of 4.5 km/h. The experiment design for reseach wes composed two experimentation. The first experiment was to examine the muscle activity of lower extremity between normal foot and excessive pronator foot during march. The second experiment was to examine the muscle activity of lower extremity between wearing orthotics and no wearing orthotics. These data were analyzed by the averaged integral EMG and the mean power frequency. The analyzed results were compared by independent T-test method and paired T-test method of SPSS(windows version 12.0). The result of the study were the muscle activity on pronator foot tend to increase during march but a statistically significant increase in muscle fatigue of vastus lateralis and fibularis longus. A statistically significant decrease in muscle activity of anterior tibialis and fibularis longus and fatigue occurred using the customized foot orthotics in volunteers with excessive pronation foot compared to volunteers with normal foot. Clinically, the application of orthotics for the soldiers with excessive pronation foot appears to delay muscle fatigue and prevent from variable foot injuries. This may contribute to enhancing fighting efficiency.
A Kinematic Characteristics of Throwing Performance on Period When Blind's became Sightless
Choi, Jung-Kyu ;
Korean Journal of Sport Biomechanics, volume 18, issue 2, 2008, Pages 125~139
DOI : 10.5103/KJSB.2008.18.2.125
The purpose of this study is to compare and analyze a kinematic characteristics of throwing performance among born visually impaired, postnatal visually impaired and visually correct people through their kinematic characteristics. Another purpose of this study is to prevent injury and improve blind's exercise leadership and physical abilities. Three video cameras were used and each camera's shooting velocity was 60field/sec. Then the longest thrown pose was collected and analyzed by using Kwon 3D ver. 3.1 program. The results obtained from this study were followings; 1. During release, the fastest speed of ball was visually corrected followed by postnatal visually impaired and then born visually impaired. 2. Visually corrected used wrist joint well and had wide body round range with similar motion patterns, however born visually impaired couldn't do this at all. 3. Visually corrected used waist to lead shoulder at Phase 2 while throwing ball, but some of born visually impaired and postnatal visually impaired couldn't use waist to lead shoulder. 4. Visually corrected looked at the way where ball would go, but blinds couldn't look where ball would go. 5. Not like visually corrected who show similar patterns, born visually impaired showed each different patterns and some postnatal visually impaired showed similar patterns with visually corrected. 6. While throwing ball, visually corrected showed flexible weight-movement, postnatal visually impaired were not good as visually corrected, and born visually impaired couldn't do weight-movement at all. Synthetically, this result showed that throwing motions are affected a lot by the time when people became blind.