Go to the main menu
Skip to content
Go to bottom
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 15, Issue 4 - Dec 2005
Volume 15, Issue 3 - Sep 2005
Volume 15, Issue 2 - Jun 2005
Volume 15, Issue 1 - Mar 2005
Selecting the target year
The Research for Using Method of GRF (Ground Reaction Force) on Rotational Movement in Arabesque
Gwon, An-Suk ; Lee, Geon-Beom ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 1~10
DOI : 10.5103/KJSB.2005.15.2.001
As, in relation to all movements of a human being, the movements such as mutually walking, running, rotating, and jumping are attained endlessly through the ground amid the interaction with the ground, in terms of the harmonious movement of the upper limbs and the lower limbs, related to the basic movement in ballet, the type of a movement depends on the size and direction of the force that presses down the ground (Fz, Fx, Fy) amid the interaction with the ground. Therefore, aiming to correctly and efficiently perform a rotational movement in Arabesque, this study analyzed factors of the force manifestation through GRF (Ground Reaction Force), by dividing into preparing, stepping, standing, rotating, and finishing stages (events (1)
(5)), targeting the subjects of 4 elite female students who majored in ballet. 1. At the No.5 position of the preparing stage, It is necessary that support the ground with left and right foot balance, 2. As the stepping stage is the phase ranging from the event (2), in which a plie movement of bending a knee is started, to the event (3) of stretching a knee, Rebunding motion is not good, and One have a position with ankle and knee flextion condition in order to stretch strengthly in event (3) position 3. At the event (1) position, It is necessary that exert the Fz reaction force at the event (3) position. Because large stretch force help to have a toe on position easily and show a active motion 4. In order to have a stand and rotation motion smoothly, One need a muscle strength training for ankle extension, knee extension, control horizental force
Kinematical Analysis of Heel-Brake Stop in Inline Skate
Han, Jae-Hee ; Lim, Yong-Kyu ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 11~20
DOI : 10.5103/KJSB.2005.15.2.011
This study has a purpose on contributing to apprehend safe and right way to stop to the inline skate beginners and to the instructors who teaches line skating on the basis for the result of the kinematical analysis on Heel brake stop movement of the inline skate, focusing on the displacement on COG, angle displacement of ankle joint, angle displacement of knee joint, angle displacement of hip joint, using a 3D image method by DLT. To achieve this goal, we analysed the kinematical factor of the 3 well-trained inline skating instructors and obtained the following results. 1. During the movement of heel-brake stop, when strong power was given to a stable and balanced stop and the lower limbs, if the physical centroid is lowered the stability increases, and if it is placed high from the base surface, as the stability decreases compared to the case of low physical centroid, we should make a stop by placing a physical centroid in the base surface and lowering the hight of physical centroid. 2. To make a stable and balanced stop and to provide a strong power to the lower limbs, it is advisable to make a stop by decreasing an angle displacement of ankle joint during a "down" movement. In case of the left ankle joint, in all events and phases the dorsiflexion angle showed a decrease. Nevertheless, in the case of the right ankle joint, the dorsiflexion angle shows an increase after a slight decrease. The dorsiflexion angle displacement of ankle joint can be diminished because of the brake pad of the rear axis frame of the right side inline skate by raising a toe, but cannot be more decreased if certain degree of an angle is made by a brake pad touching a ground surface. To provide a power to a brake pad, it is recommended to place a power by lowering a posture making the dorsiflexion angle of the left ankle joint relatively smaller than that of the right ankle. 3. To make a stable and balanced stop and to add a power to a brake pad, the power must be given to the lower limbs in lowering the hight of physical centroid. For this, it is recommended to make a down movement by decreasing the flexion angle of a knee joint and it is necessary to make a down movement by a regular decrease of the angle displacement of knee joint rather than a swift down movement in every event and phase. 4. The right angle displacement of hip joint is made by lowering vertically the hight of physical centroid as leaning slightly forward. If too narrow angle displacement of hip joint is made by leaning forward too much, the balance is lost during the stop by placing the center in front. To make a stable and balance stop and to place a strong power to the lower limbs, it is recommendable to make a narrow angle by lower the hip joint angle. However, excessive leaning of the upper body to make the angle too narrow, can cause an instable stop and loss of physical centroid. After this study, it is considered to assist the kinematical understanding during the heel brake stop movement of the inline skate, and, to present basic data in learning a method of stable and balanced stop for the inline skating beginners or for the inline skate instructors in the present situation of the complete absence of the study in inline skating.
Determination of Performance Determinant Factors in Snatch Weightlifting
Moon, Young-Jin ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 21~29
DOI : 10.5103/KJSB.2005.15.2.021
The Purpose of this study was to seek determinant factors through analysis of 65 snatch skill kinematic factors of Athletics participated in 2001 Asian weightlifting competetion. The conclusion were as follows ; 1. In order to enhance snatch skill, when barbell move on knee position, One should be flex knee joint to 105-110 degree, and In pull motion, One should be move powerful extension of knee and hip joint. 2. In last pull motion, One try to make more lock out motion than extra extention motion of hip joint 3. In order to enhance snatch skill, It is inportant that elevate barbell highly by last pull motion through powerful knee extention, poweful hip flextion and One should be make lock out motion fast in the same time. 4. In order to enhance snatch skill, anterior-posterior movement width of shoulder joint should be small. 5. In order to enhance snatch skill, Hip joint should be move vertically on start and lock out phase, but In pull phase, extension motion of hip joint shoulde be performed more largely and powerfully.
Biomechanical Research of Soccer Footwear
Jin, Young-Wan ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 31~39
DOI : 10.5103/KJSB.2005.15.2.031
The Purpose of this study was to reveal the biomechanical difference of two soccer footwear(soft ground footwear and hard ground footwear). Secondly, the purpose of this study was to clarify how each type of soccer footwear effects soccer players, which will provide scientific data to coaches and players, to further prevent injuries and to improve each players capacity. The result of comparative analysis of two soccer footwear can be summarized as below. The comparison of the very first braking force at walking found distinctive factors in the statistical data(t
Analysis of Plantar Foot Pressure During Golf Swing Motion of Pro & Amateur Golfer
Lee, Joong-Sook ; Lee, Dong-Ki ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 41~55
DOI : 10.5103/KJSB.2005.15.2.041
In this study, weight carrying pattern analysis and comparison method of four foot region were suggested. We used three types of club(driver, iron7, pitching wedge). This analysis method can compare between top class golfer and beginner. And the comparison data can be used to correct the swing pose of trainee. If motion analysis system, which can measure the swing speed and instantaneous acceleration at the point of hitting a ball, is combined with this plantar foot force analysis method, new design development of golf shoes to increase comfort and ball flight distance will be available. 1. Regional change of force acting, in address, is evenly distributed on both feet. In back swing top, 76% on right foot, 75% on left foot as impact, and 86% on left foot as finish. As regional force acting, in address, pros get high marks on rare and inside of right foot and rare and outside for amateurs. In back swing top, it is higher as fore and inside of left foot, pros as rare part of right foot and amateurs as forefoot. In impact, it is higher for pros and amateurs in outside and rare part of left foot and fore and inside of right foot. In finish, for both pros and amateurs, it is higher for outside and rare parts of left foot. 2. For each club, forces are evenly distributed on both feet in address. In back swing top, the shorter a club is, the higher impact on right foot and the higher finish distribution on left foot. For all the clubs used, in each region, pros get higher on rare and inside of right foot and as amateurs on rare and outside of left foot in address. In back swing top, for all clubs, pros get higher on rare and outside of right foot as fore and outside for amateurs. In impact acting, for all clubs, rare and outside of left foot get higher. In finish, force concentrates on rarefoot. 3. On both feet force, right foot forces of amateurs is higher than those of pros in back swing top. In impact and finish, pros get higher on left foot.
An Application of Triple Segmental System in Golf Swing through an Inverse Dynamics Function
Lim, Jung ; Moon, Gun-Pil ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 57~67
DOI : 10.5103/KJSB.2005.15.2.057
The purpose of this study was to analyze the kinetic factors of the golf driver swing using the Inverse Dynamics function. For this purpose, joint force were calculated. In order to test the possibility of Inverse Dynamics function(motion-dependent interaction), a triple segmental system was set for wrist, left shoulder and lumbar and joint force working on the anatomical joint region was estimated. For this study, 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular`s equation was used to produce some kinematic data, which were used to calculate joint force and torque with Newton`s function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint force was generated on wrist, shoulder and lumbar joints in the direction of the target, and that the joint force was stronger in the direction of target immediately before impact. The joint force was generated towards the target to activate the nodes, and then, it was generated in the reverse direction to increase the speed during impact.
The Influence of Rearfoot Motion Control through Marathon Shoes On and Off
Kim, Young-Jae ; Jang, Sung-Il ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 69~81
DOI : 10.5103/KJSB.2005.15.2.069
In this study using two-dimensional system of the analysis of image, when normal males in their twenties who have normal foot and step with heel first are walking and running, they who are wearing running shoes or barefoot are testing and comparing the exchange factors of heel control. There are following results of this test by verifying them with T-Test. 1) When they are running, there are two big different gap which is
between barefoot and wearing the running shoes. The former is
and the latter is
. But it is not statistically significant. The angle of first step with heel is
with barefoot and
with wearing the running shoes. In this case, it is statistically significant(p<.01) 2) When they are running, the angle of the Achilles` tendon has different gap which is
between barefoot and wearing the running shoes. The former is
and the latter is
. It is not statistically significant. The angle of minimal step with heel is
with barefoot and
with wearing the running shoes. In this case, it is statistically significant(p<.01). 3) In the angle of the Achilles` tendon and the angle of first step with heel, when they are walking, the angle of the Achilles` tendon has different gap which is
between barefoot and wearing the running shoes. The former is
and the latter is
. It is not statistically significant. The angle of first step with heel is
with barefoot and
with wearing the running shoes. It is not statistically significant. 4) In the angle of the take-off of Achilles` tendon, when they are walking, the angle of the take-off of Achilles` tendon has different gap which is
between barefoot and wearing the running shoes. The former is
and the latter is
. It is statistically significant(p<.05). Therefore, they are running, the angle of the take-off of Achilles` tendon is
with barefoot and
with wearing the running shoes. It is statistically significant(p<.05).
Accuracy and Consistency of Three-Dimensional Motion Analysis System
Park, Young-Hoon ; Youm, Chang-Hong ; Seo, Kook-Woong ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 83~92
DOI : 10.5103/KJSB.2005.15.2.083
Computer-assisted motional analysis is a popular method in biomechanical studies. Validation of the specific system and its measurement are fundamental to its application in the areas. Because the accuracy and consistency of a particular system provide the researchers with critical information to assist in making judgements regarding the degree to which inferences can be drawn from measurement data. The purpose of this study was to assess the accuracy and consistency of the Kwon3D motion analysis system. Validation parameters were five lengths from eight landmarkers in combination with the DLT reconstruction error values, digitizing monitor resolutions, and numbers of control points. With the best setting, Kwon3D`s estimations of 260cm, 200cm, 140cm, 100cm, and 20cm were
, respectively. There was no significant DLT error value difference between two monitor resolutions, but 0.27cm significant difference in 260cm estimation. There were significant differences in 260cm and 200cm estimations between with 33-control-point DLT error and with 17-control-point DLT error, but no in 140cm, 100cm, and 20cm estimations. Test-retest results showed that Kwon3D measurements were highly consistent with reliability coefficients alpha of .9263 and above.
The Influence of Step Length at Different Walking Speed on the Moment of the Lower Limb Joint
Kim, Ro-Bin ; Jin, Young-Wan ; Moon, Gon-Sung ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 93~102
DOI : 10.5103/KJSB.2005.15.2.093
The purpose of this study was to examine the effect of step length on the joint moment. The subjects were 4 undergraduate and graduate students in their 20s with normal legs. The subjects were individually tested by the running timer at the walking speed of 0.67m/s, 134m/s, and 2.46m/s. The step length was regulated to -10% of normal, normal and +10% of normal step length using foot print. The walking performances of each subjects were filmed using a high speed video camera. The raw data were analyzed by LabVIEW Graphical Program and these data were analyzed by ANOVAs and Scheffe. The results of this study were as follows: The maximum dorsiflexion moment of the ankle joint increased as the step length increased only at the fast walking speed. Although there wasn`t significant difference shown in the plantar flexion moment, regular pattern in the plantar flexion moment which increased as the step length increased was found. The first maximum extension moment of the knee joint increased only at the normal walking speed, but there appeared no significant difference in the maximum flexion and second extension moment. The maximum extension moment of the hip joint increased at the normal and fast walking speed. Although there wasn`t significant difference, regular pattern in flexion moment which increased as the step length increased was found.
A Study of Ground Reaction Forces During Professional Golfer`s Swing with Different Golf Clubs
Hur, You-Jein ; Moon, Gun-Pil ; Lim, Jung ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 103~111
DOI : 10.5103/KJSB.2005.15.2.103
The purpose of this study was to analysis golf swing in accordance with each club using ground reaction force data. The subject of this study was current professional golf players in Korea. Golf clubs used for this study were driver, iron4, iron7, and pitching. The ground reaction force for left and right foot was collected by one Kistler and one Bertec force platforms. Also collected visual data by NC high speed camera to check the phase which was composed of address, top of backswing, impact and finish. Sampling rate was 600Hz both ground reaction forces data and visual data. The conclusion are as follows. 1. An aspect of change for ground reaction force was that the weight between the left foot and right foot were contrary to each other in general as the phase. 2. Without regard to the type of golf club, the ratio of necessary ground reaction forces for each phase in accordance with address, top of backswing, impact, and finish was comparatively identical. 3. According to the type of golf club, the tendency of Fy was not varied. In terms of Driver, at the moment of impact, the weight of foot-both right and left-was moved to the movement direction of golf because of the rotation force from swing.
Development of Putting Grip Sensor System
Tack, Gye-Rae ; Lim, Young-Tae ; Yoon, Jeong-Min ; Kim, Hyung-Sik ; Yi, Jeong-Han ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 113~117
DOI : 10.5103/KJSB.2005.15.2.113
As a preliminary study of finding the relationship between the force at the grip and the success rate during putting stroke, the putting grip sensor system using FSR sensors was developed. The system consisted of the hardware which had the sensor part with 8 sensors per putting glove and data acquisition part as well as the software which had the real-time monitoring program and the offline post-processing program. After experiments with elite-golfer using this system, it is possible to suggest the proper force ranges at the grip during putting stroke.
Kinematical Analysis of Ropez Motion in Horse Vault
Back, Jin-Ho ; Lee, Soon-Ho ; Choi, Kyu-Jung ; Moon, Young-Jin ; Kim, Dong-Min ; Park, Jong-Hoon ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 119~127
DOI : 10.5103/KJSB.2005.15.2.119
The purpose of this research helps to make full use for perfect performance by grasping the defects of Ropez motion performed by athlete CSM who was under the training for the 28th 2004 Athene Olympic Garnes, and by presenting complementary methods. For the better Ropez motion which had been performed by CSM for the 1st dispatch selection test and the final for the 28th Athene Olympic Game was analyzed with 3-dimensional cinematographic method. Here are the conclusions: 1. During the board contact phase, powerful kicking and rapid forward flexion motion of upper body make increasing vertical velocity of C. O. G and enlarging body angle. 2. It was indicated that rapid forward flexion motion of upper body during the board contact phase get a large body angle in horse take-off. 3. rapid forward flexion motion of upper body during the board contact phase makes a longer time at horse contacting phase. It showed that this result increased velocity of horse take-off causing by powerful blocking motion. 4. Increasing of air-borne height during pre- flight phase, makes a higher C. O. G; and larger angle of hip, angle of knee and body angle in the landing phase. And it revealed that these results have a stable landing.
The Jumping Performance Strategy over 8 meters in National Long Jumpers through the Kinematic Variable Researches
Ryu, Jae-Kyun ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 129~138
DOI : 10.5103/KJSB.2005.15.2.129
The purpose of this study was to investigate the techniques used by long jumpers who recorded over 8meters in 2002 Busan Asian Game and 2003 Daegu Universiade. The kinematic characteristics from the last three stride to takeoff at the takeoff board were analyzed such as velocities, heights and angles. The real-life three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation procedure. The conclusion were as follows; 1. The height variation who recorded over 8 meters of center of gravity of the jumpers at the last stride was under 8cm. In order to record over 8meters the national long jumpers should have under 10cm height variation. 2. In the approach phase the horizontal velocity of the jumpers should reach to 10.5m/s in last three strides and 9.79m/s in touch down at take off board. 3. The horizontal velocity at take off board must have over 8.51m/s and the vertical velocity must have 3.75m/s simultaneously in order to record 8meters. 4. The forward body lean angle should have over 20degrees with pushing the take off board in forwarding movement. The appropriate body variation range ratio between take off and touch down should be 1.2 vs 1 and the trunk angle at touch down on the board should be close to the erect posture for higher body flight.
The Effectiveness of Selected Stretching Exercise by Surface EMG on Backpain Patients
Park, Jung-Sik ; Lee, Kyoung-Il ; Lee, Chul-Gab ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 139~146
DOI : 10.5103/KJSB.2005.15.2.139
We selected six kinds of stretching exercises that can be easily acquired and put to practical use by back pain patients and arranged the practicing order of the exercising method after measuring the % MlVC of the muscle power when a normal person was exercising with a surface EMG. Among the patients complaining of back pain, 20 case groups were given the selected exercise and physical therapy, and 20 control groups were only given a physical therapy. Before and 2 weeks, 4weeks, 6 weeks and 8 weeks after the exercise therapy, a muscle power was measured with a fitness machine and the effectiveness of the exercise was compared. After six weeks difference of the muscle power between the case group and control group was shown, and after 8weeks the case group manifested the stronger muscle power than that of the control group in both male and female. Exercising therapy clearly seems to be helpful in strengthening the muscle power of the back pain patients.
Effects of Obesity on Lumber Strength and Visual Analogue of Back Pain in Disc Surgical Operated Patients after Rehabilitation
Lee, Chang-Jin ; Lim, Young-Tae ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 147~153
DOI : 10.5103/KJSB.2005.15.2.147
The purpose of this study were to compare the differences of isometric lumber extension strength and subjective pain degrees between obesity patients group and normal body fat group in disc surgical operated patients. The research purposed to indicate how isometric lumbar extension exercise for 12 weeks affected to lumbar strength and visual analogue scale of patients suffered by chronic back pain. The subjects were 65 low back pain patients(male 30, female 35)who had disease on lumbar in W hospital. The lumbar extension strength was measured at seven degrees of angles, which were
before and after the exercise program. We got the results of subjective pain degree using the modified visual analogue scale(VAS) of Lawlis et al(1989) and measured the maximal isometric lumbar strength of all subjects using MedX lumbar extension machine. Results were as follows; After the exercise, the lumbar extension strength of normal body fat patients groups included males and female were greater than that of the obesity patients groups in all angles(p<.05). The visual analogue scale of chronic back pain patients was decreased significantly after the exercise(p<.05). The results showed the significance between the lumbar extension strength and the visual analogue scale of chronic back pain patients and showed that the isometric lumbar extension exercise decreased the subjective pain degrees of visual analogue scale with and increased lumbar extension strength. The correlation between the visual analogue scale and the %body fat of chronic back pain patients was no significant after exercise. Therefore, the lumbar extension strength exercise is needed for improvement of back strength, decrease of %body fat.
Analysis of Muscle Activities of Lower Extremity in Jumping Pattern
Lee, Sung-Cheol ; Hwang, In-Seong ; Cho, Young-Jae ; Kim, Sun-Jung ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 155~165
DOI : 10.5103/KJSB.2005.15.2.155
The purpose of this study was to compare the muscle activities of Double Legged Jump (DLJ) and Single Legged Jump (SLJ) by the normalization of muscle activity. Eight college students without the lower extremity injuries were selected as subjects for collecting EMG data of vastus medialis and gastrocnemius. The entire section of motion was established as eccentric and concentric contractions, and each of the contractions was divided into three sections with equal timing intervals, which becomes a total of 6 phases. The EMG data of each phase was integrated and normalized. The muscle activities of the vastus medialis for both eccentric and concentric contractions were significantly different between DLJ and SLJ(p<.05). The increase in overall muscle activity of SLJ was 33.6%. Approximately, there was an increase of 25.9% in eccentric contraction and 40% in concentric contraction. Moreover, the data of the muscle activity of gastrocnemius was similar to the data of the muscle activity of vastus medialis. In conclusion, this research suggests muscle activity of a certain motion can be normalized for an analysis of another motion.
The Kinetic Analysis of the Lower Extremity Joints when Performing Uchi-mata by Uke`s Posture in Judo
Yoon, Hyun ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 167~183
DOI : 10.5103/KJSB.2005.15.2.167
The purpose of this study was to analyze the kinetical variables of the lower extremity joints when performing uchimata(inner thigh reaping throw) by uke(receiver)`s two posture(shizenhon tai), jigohon tai), by voluntary resistance level(VRL) in judo. The subjects, who were for 3 male Korean national representative judokas(elite group : EG) and 3 male representative judokas of Korean University(non-elite group: NEG), and were filmed 4 DV video cameras(60fields/sec.), that posture of uke were shizenhon-tai (straight natural posture), jigohon-tai(straight defensive posture), VRL of uke was 0%. The selected trials were subject to 3-dimensional film motion analysis and ground reaction force(MRF) analysis. The kinetical variable of this study were temporal, postures( ankle and knee angle of attacking leg), that were computed through video film analysis, MRF at events were obtained from the ground-
reaction force analysis by AMTI force plate system. When performing uchi-mata according to each posture and by VRL, from the data analysis and discussion, the conclusions were as follows : 1) Temporal variables : total time-required(TR) when performing uchi-mata was shown EG 0.13sec the shorter than NEG(o.77sec.) in shizenhon-tai. and EG 0.17sec the shorter than NEG(o.76sec.) in jigonhon-tai. Also, all of two groups` jigohon-tai(0.68sec.) were faster than shizenhon-tai(0.71 sec.). 2) The posture variables : The angle of ankle in attacking when performing were plantar flexion in EG, and dorsi flexion in NEG by shizenhon-tai and jigohon-tai posture. The angle of knee in attacking when performing were extension in EG and NEG, but range of extension in EG were larger than in NEG. 3) MRF : Vertical MRF when performing uchi-mata was shown the strongest in the 2nd stage of kake phase(2.23BW) by EG in both posture, and it was same value by NEG(2.23BW), but shizenhon-tai (2.28BW), jigohon-tai(1.64BW), respectively.
Change of Plantar Pressure Distribution according to Stance Patterns during Tennis Forehand
Lee, Tae-Keun ; Kim, Seung-Jae ; Choi, Ji-Young ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 185~196
DOI : 10.5103/KJSB.2005.15.2.185
Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance and it is very important to know the patterns of plantar pressure distribution for the better understanding of forehand stroke. Therefore, the purpose of this study was to investigate the change of plantar pressure distribution according to close, square and open stance patterns during forehand stroke in tennis. Three high school tennis players were recruited for the study and required to perform forehand stroke five consecutive trials in the condition of open, square and close stance. The forehand strokes were filmed with two digital video cameras and measured with pedar system for plantar pressure. The plantar regions under the foot were divided into 3 regions, which were forefoot, midfoot, and rear foot.. In conclusion, the first hypothesis, "The plantar pressure of close stance during forehand stroke would be distributed more largely to the left foot.", was rejected and the result showed that The plantar pressure of close stance during forehand stroke was distributed transferring from right foot to left foot similar to square stance. The second hypothesis, "The plantar pressure of square stance during forehand stroke would be distributed transferring from right foot to left foot." was accepted. The third hypothesis, "The plantar pressure of open stance during forehand stroke would be distributed more largely to the right foot.", was accepted.
Analysis of the Body Segment Kinematics by Lap Time during Men`s 5,000m Racing
Chung, Nam-Ju ;
Korean Journal of Sport Biomechanics, volume 15, issue 2, 2005, Pages 197~207
DOI : 10.5103/KJSB.2005.15.2.197
The purpose of this study was to investigate the body segment kinematics by lap time during men`s 5,000m racing. The subjects in this study were 4 male athletics who take part in the competition. The two dimension motion analysis with DLT(direct linear transformation) method was executed using digital video cameras. The following conclusion was that : It was shown that top ranking in a competition is continuous race pattern and the last Lap time is the most fast. It was shown that top ranking in a competition is continuos the stride length and it was the largest in the last Lap time. It was shown that according to the passing Lap time trunk frontal angle was decreasing and shoulder angle was continuous.