• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.259-278
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• 2002

This study divided straight success, pade success and failure with 7male golfers who have experiences more than 3 years, analyzed kinematic factors of golf swing to suggest scientifically. The conclusions were follows. 1) The wrist angle has significant difference in straight success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. 2) The body twist angle has no significant difference in straight success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. 3) The shoulder joint rotation angle has no significant difference in success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. 4) The left hip joint vertical angle has no significant difference in straight success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. 5) The hip joint rotation angle has no significant difference in straight success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. 6) The trunk angle has no significant difference in straight success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. 7 )The left knee joint angle has no significant difference in straight success, pade success and failure when swing of every pattern. There is no significant difference in pade success and failure. This study divided golf swing motion of pattern change in straight success, pade success and failure and analyzed the kinematic factors by 3-dimension cinematography to improve performance. In the future, many researchers have to study kinematic analysis to improve performance in every events.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.279-293
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• 2002

In the study the subjects who 10 university golfers act, and the kinetic factors were analyzed by the ground reaction system. the conclusion are as follows. 1) In the golf putting swing, the ground reaction factors of sagital plane in aspect are showen that the left and right foot sufficient difference, in the level of p <.05. 2) In the golf putting swing, the ground reaction factors of frontal plane in aspect is showen that the left foot has no significant difference in AD BS in the level of p < .05. In success, IP, FS. It can show significant difference. In addition, the right foot is shown the success, There is significant difference. 3) In the golf putting swing, the ground reaction factors of the vertical plane in aspect are shown that the left foot has no significant difference in BS, FS in the level p < .05. In success, AD, IP. It can show significant difference. In addition, the right foot is shown the success, There is significant difference. 4) In the golf putting swing, the ground reaction factors of torque in aspect are shown that the left foot had no significant difference in BS in the level p < .05. In success, AD, IP, FS. It can show significant difference. In addition, the right foot has no significant difference in IP in the level p < .05. AD, BS, FS. There is significant difference. The summarized conclusions are as follows. The first that the power of sagital plane needs the motion which can get the good power change in the stabilized pose. The second is that the small motion can make good putting in stabilized pose. The third is that the body weight move to the direction of the ball. The fourth is that the putting which looks perfect oscillation is good motion.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.149-163
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• 2006

The purpose of this study was to compare the lower extremity's joint and segment coupling patterns between forward and backward running in subjects who were twelve healthy males. Three-dimensional kinematic data were collected with Qualisys system while subjects ran to forward and backward. The thigh internal/external rotation and tibia internal/external rotation, thigh flexion/extension and tibia flexion/extension, tibia internal/external rotation and foot inversion/eversion, knee internal/external rotation and ankle inversion/eversion, knee flexion/extension and ankle inversion/eversion, knee flexion/extension and ankle flexion/extension, and knee flexion/extension and tibia internal/external rotation coupling patterns were determined using a vector coding technique. The comparison for each coupling between forward and backward running were conducted using a dependent, two-tailed t-test at a significant level of .05 for the mean of each of five stride regions, midstance(1l-30%), toe-off(31-50%), swing acceleration(51-70%), swing deceleration(71-90), and heel-strike(91-10%), respectively. 1. The knee flexion/extension and ankle flexion/extension coupling pattern of both foreward and backward running over the stride was converged on a complete coordination. However, the ankle flexion/extension to knee flexion/extension was relatively greater at heel-strike in backward running compared with forward running. At the swing deceleration, backward running was dominantly led by the ankle flexion/extension, but forward running done by the knee flexion/extension. 2. The knee flexion/extension and ankle inversion/eversion coupling pattern for both running was also converged on a complete coordination. At the mid-stance. the ankle movement in the frontal plane was large during forward running, but the knee movement in the sagital plane was large during backward running and vice versa at the swing deceleration. 3. The knee flexion/extension and tibia internal/external rotation coupling while forward and backward run was also centered on the angle of 45 degrees, which indicate a complete coordination. However, tibia internal/external rotation dominated the knee flexion/extension at heel strike phase in forward running and vice versa in backward running. It was diametrically opposed to the swing deceleration for each running. 4. Both running was governed by the ankle movement in the frontal plane across the stride cycle within the knee internal/external rotation and tibia internal/external rotation. The knee internal/external rotation of backward running was greater than that of forward running at the swing deceleration. 5. The tibia internal/external rotation in coupling between the tibia internal/external rotation and foot inversion/eversion was relatively great compared with the foot inversion/eversion over a stride for both running. At heel strike, the tibia internal/external rotation of backward running was shown greater than that of forward(p<.05). 6. The thigh internal/external rotation took the lead for both running in the thigh internal/external rotation and tibia internal/external rotation coupling. In comparison of phase, the thigh internal/external rotation movement at the swing acceleration phase in backward running worked greater in comparison with forward running(p<.05). However, it was greater at the swing deceleration in forward running(p<.05). 7. With the exception of the swing deceleration phase in forward running, the tibia flexion/extension surpassed the thigh flexion/extension across the stride cycle in both running. Analysis of the specific stride phases revealed the forward running had greater tibia flexion/extension movement at the heel strike than backward running(p<.05). In addition, the thigh flexion/extension and tibia flexion/extension coupling displayed almost coordination at the heel strike phase in backward running. On the other hand the thigh flexion/extension of forward running at the swing deceleration phase was greater than the tibia flexion/extension, but it was opposite from backward running. In summary, coupling which were the knee flexion/extension and ankle flexion/extension, the knee flexion/extension and ankle inversion/eversion, the knee internal/external rotation and ankle inversion/eversion, the tibia internal/external rotation and foot inversion/eversion, the thigh internal/external rotation and tibia internal/external rotation, and the thigh flexion/extension and tibia flexion/extension patterns were most similar across the strike cycle in both running, but it showed that coupling patterns in the specific stride phases were different from average point of view between two running types.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.239-246
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• 2018

In this study, we analyzed the balance of the both legs and the kinematic analysis of the upper limb segments and joints during archery shooting and compared the differences according to the scores. 9 K-university elite archery athletes participated. Each archer was asked to shoot 3-shots and 5-ends on a 122 cm target at a distance of 70 m. Seven infrared cameras (Qualisys, sweden) and two force plates (Kistler, Switerland) were used to calculate the upper limb segments and joint movements and the center of pressure (COP). When the archers shot 8 points, range of motion of elbow joint angle on drawing-arm and mediolateral COP range of motion on the left foot were larger than when 9-10 points were shot (p<.05). In order to maintain a high score in the archery game, constant balance is required, and the balance of the left foot supporting the bow during the shooting is an important factor. In addition, minimizing elbow joint movement of the drawing-arm supporting the bow will help stabilized shooting.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.143-151
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• 2015

The purpose of this study was to investigate temporal and spatial variations, and moments of the lower extremities of gait while playing the game with smartphone under different curb-heights. Ten male elementary school students(from 10 years to 13 years old) participated in this study. Twelve infrared cameras(Oqus-500) and two force plates(9260AA) were used for collecting data and these were processed via Visual 3D software. In conclusion, with or without smartphone and with different curb-heights, the spatial and temporal parameters of walking were not the same and coefficients of variations were not consistent. The maximum joint moments of the lower extremities with or without smartphone were not statistically significant but those of hip and ankle joint were statistically significant with regard to the different heights of the curbs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7285-7292
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• 2015

The purpose of this study was to investigate possibility of a forward gait with backward mechanism(dance gait) as rehabilitation and/or walking exercise by means of biomechanical variables. Thirteen professional women dancers(age, $21.1{\pm}1.3yrs$; height, $159.3{\pm}7.2cm$; body mass, $45.1{\pm}8.4kg$)participated in this study. We found that speed, stride length and double limb support time of a dance gait were more greater than backward gait, but stride width of dance gait less than a backward gait. Maximum RoMs, moments and powers of the lower limb joints on a dance gait were more frequent than a backward dance. These results were judged to be sufficient by the possibility of dance gait as rehabilitation and walking exercise.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.207-216
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• 2007

The purpose of this study was to biomechanical analysis Judo's Kuzushi throwing motion in order to increase the effectiveness of Nage-waja(throwing technique). The Tori was a Judo player with 18 years experience(4th degree) while the Uke was a player with 2 years experience(1st degree). The kinematic data was captured using the Vicon motion system (7 cameras) and the kinetics were recorded by force plates(2 AMTI). The following were the results; While leaning to the front the subject's trunk's angle was $14.5^{\circ}$, the lower limbs angle was $23.8^{\circ}$, knee angle was $179.6^{\circ}$ and the vertical reaction of the left leg was 325.42N(BW 0.34) and the right leg was 233.7N(BW 0.47). While leaning back the subject's trunk's angle was $11.3^{\circ}$, the lower limbs angle was $4.1^{\circ}$, knee angle was $1761^{\circ}$ and the vertical reaction of the left leg was 299.53N(BW 0.43) and the right leg was 441.7N(BW 0.64). While leaning to the left the subject's trunk's angle was $30.8^{\circ}$, the lower limbs angle was $2.7^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 711N(BW 1.03) and the right leg was 9.2N(BW 0.01). While leaning to the right the subject's trunk's angle was $36.5^{\circ}$, the lower limbs angle was $10.4^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 13.2N(BW 0.02) and the right leg was 694.7N(BW 1.01). While leaning to the left front corner the subject's trunk's angle was $19.8^{\circ}$ (front) and $15.1^{\circ}$ (left), the lower limbs angle was $17.8^{\circ}$ (front) and $2.4^{\circ}$ (left), knee angle was $177.8^{\circ}$ (front) and $173.9^{\circ}$(left), and the vertical reaction of the left leg was 547.4N(BW 0.8) and the right leg was 117.8N(BW 0.17). While leaning to the right front corner the subject's trunk's angle was $15.4^{\circ}$ (front) and $17.7^{\circ}$ (right), the lower limbs angle was $21.1^{\circ}$, (front) and $5.7^{\circ}$ (right), knee angle was $175.5^{\circ}$ (front) and $178.9^{\circ}$(right), and the vertical reaction of the left leg was 53N(BW 0.08) and the right leg was 622.4N(BW 09). While leaning to the left rear corner the subject's trunk's angle was $9.2^{\circ}$ (back) and $13.8^{\circ}$ (left), the lower limbs angle was $2^{\circ}$, (back) and $5.7^{\circ}$ (left), knee angle was $175.5^{\circ}$ (back) and $172.8^{\circ}$(left), and the vertical reaction of the left leg was 698.2N(BW 1.02) and the right leg was 49.6N(BW 0.07). While leaning to the right rear corner the subject's trunk's angle was $8.9^{\circ}$ (back) and $19.6^{\circ}$ (right), the lower limbs angle was ${0.6^{\circ}}_"$ (back) and $3.1^{\circ}$ (right), knee angle was $174.6^{\circ}$ (back) and $175.6^{\circ}$(right), and the vertical reaction of the left leg was 7.2N(BW 0.01) and the right leg was 749.4N(BW 1.09). It was observed that during the Judo motion Kuzushii the range of the COM varied from $26.5{\sim}39.9cm$. It was concluded that the upper body leaned further than the lower body as there was knee extension. There was high left leg reaction forces while leaning to the left and likewise for the right side. It was therefore deduced that the Kuzushi was a more effective throwing technique for the left side.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.63-87
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• 2002

The purpose of this study was to analyze the kinematic variables when Uchi-mata(inner thigh reaping throw) performing by Kumi-kata(engagement position, basic hold) types A, B(A: grasping part-behind neck lapel, B: chest lapel) in Judo with three dimensional analysis technique DLT method by videography. The subjects were four male judokas who have been training in Yong-In University(YIU), on Korean Representative level and Uchi-mata is their tokui-nage(favorite technique), the throwing form was filmed on two S-VHS 16mm video camera( 30frame/sec. Panasonic). Kinematic variables were temporal, posture, and COG. The data collection was performing by Uchi-mata. Six good trials were collected for each condition (type A, B) among over 10 trials. The mean values and the standard deviation for each variable were obtained and used as basic factors for examining characteristics of Uchi-mata by Kumi-kata types. The results of this analysis were as follows : 1) Temporal variables The total time elapsed(TE) by Uchi-mata of types A, B were 1.45, 1.56 sec. respectively. Types A shorter than B. 2) Posture variables In performing of Uchi-mata, the range of flexion in type A, left elbow was $45^{\circ}$ and B was $89^{\circ}$ from Event 2(E2) to Event 6(E6). Type A and B were quite different in right elbow angle in Event1(E1). Left shoulder angle of type A was extended and type B was flexed in E4. Both types right shoulder angles were showed similar pattern. Also both hip angles(right/left) were showed similar pattern. When type A performed Uchi-mata the knee-angle of supporting foot showed $142^{\circ}$in the 1st stage of kake phase[KP], and extended to $147^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $86^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $126^{\circ}$in the 1st stage of KP, and extended to $132^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $106^{\circ}$in the 1st stage of KP, and extended to $121^{\circ}$in the 2nd stage of KP. When type B performed Uchi-mata the knee-angle of supporting foot showed $144^{\circ}$in the 1st stage of KP, and extended to $154^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $92^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $132^{\circ}$in the 1st stage of KP, and extended to $140^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $103^{\circ}$in the 1st stage of KP, and extended to $115^{\circ}$in the 2nd stage of KP. During Uchi-mata performing, type A showed pulling pattern and type B showed lift-pulling pattern. As Kumi-kata types, it were different to upper body(elbow, shoulder angle), but mostly similar to lower body(hip, knee, ankle angle) on both types. 3) C. O. G. variables When the subjects performed Uchi-mata, COG of type A, B up and down in vertical aspect was 71cm, 73.8cm in height from the foot in the 2nd stage of KP. As Kumi-kata types, it were different on medial-lateral direction aspect but weren't different in Kuzushi phase on vertical direction aspect.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.345-359
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• 2002

The purpose of the study was to provide the fundamental data to instruct athletes through the analysis athletes' movement in javelin. Three athletes in the level of national representative were participated in this study. The study analyzed kinematic variables(lead foot and releasing javelin) through 3-D analysis and obtained the following results. 1. During withdrawal, it is important to maintain of running horizontal velocity. 2. It was showed that throng average height was $84{\pm}3.3%$ and javelin adequative degree, Among the athletes, $S_2$ who had the best record was released the javelin with the fast velocity, but throw the javelin with the less releasing velocity. 3. $S_2$ released after lead foot were completely landed and therefore it is no problem in a kinematic aspect. However, $S_1$ angle was too small. it caused increase of release velocity to be prevented. 4. $S_2$ showing the best result indicated shorter in duration time. Generally, the shorter duration time in release phase showed the longer release distance. Especially $S_1$ and $S_3$ showing the worse result indicated the longer duration time in preparatory phase, causing the breakup of force. Therefore to improve the record, it should be decreased the duration time in preparatory phase. 5. Compared with $S_1$ and $S_3$, $S_2$ showing the best record indicated the higher velocity in center of mass, trunk, upper arm, lower arm and hand That is the higher velocity of upper arm at release leaded the better velocity transfer from upper arm to following lower arm and hand, these action should be considered to be helpful of better record. According to the above conclusion, when the athletic leaders cauch athletes, they should focus on maintaining knee angle, upper body and hip angle in a previous stage of release and throwing angle, throwing height, throwing velocity in a release stage.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.159-177
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• 2002

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle and the angular velocity of the air born phase and understand the control mechanism of the high-bar movement, the somersault, the double somersault, the double somersault with full twist. For this study seven well trained university gymnastic volunteered, Zatsiorky and Seluyanov(1983, 1985)'s sixteen segment system anatomical model was used for this study. For the movement analysis three dimensional cinematographical method(Arial Performance Analysis System : APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 5.1 graphical profromming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and angular velocity were defined. As a result of this study 1. As the rotation of the body increased in the air born phase the projection angle of the CM of the total increased, this resulted the increased of the max hight of the CM. 2. In three dimensional angular velocity the Z axis(vertical direction) projection angular velocity increased as the rotation of the body increased in the airborn phase, but the Y axis and the X axis projection angular velocity did not show significant differences. 3. As the rotation of the body increased in the air born phase the angular movement of the shoulder and the hip showed significant change. These movement act as the starter in the preparation phase. 4. The somersault angle, the twist angle, the tilt angle of the upper body related to the global reference frame in the releas phase the average somersault angle of the three types of high-bar movement was $57.7^{\circ}$, $38.8^{\circ}$, $39.7^{\circ}$, the average tilt angle was $-1.5^{\circ}$, $-5.4^{\circ}$, $-8.4^{\circ}$, the average twist angle was $13.4^{\circ}$, $10.6^{\circ}$, $23.3^{\circ}$. This result showed that the somersault with full twist had the largest movement.