• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.727-734
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• 2021

The purpose of this study was to analyze correlation between kinematic variables and ground slope perception ability during golf putting. 16 collegiate golfers were participated. To collect and analyze the kinematic data of putter head, SAMPutt lab was used(70 Hz). It was performed Pearson's correlation analysis using SPSS. The level of significance was at .05. As a results, right was correlated with backswing in flat. Toe-up was correlated with follow-through and left was correlated with aim, backswing, impact, follow-through, and loft in slice 1°. Toe-down was correlated with aim, backswing, impact in slice 2°. Toe-up was correlated with follow-through in hook 2°. In conclusion, it is important to improve the putting stroke through repetitive ground slope perception training.

• Korean Journal of Applied Biomechanics
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• v.26 no.3
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• pp.265-272
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• 2016

Objective: The aim of this study was to analyze X-factor, triple X-factor, and the center of pressure (COP) according to the feel of golf driver swing. Method: For this research, 9 golfers from the Korea Professional Golfers' Association (age: $30.11{\pm}2.98yrs$, height: $178.00{\pm}8.42cm$, weight: $76.22{\pm}8.42kg$, experience: $10.06{\pm}3.11yrs$) were recruited to participate in the experiment. Twelve Motion Analysis Eagle-4 cameras were installed and an image analysis was conducted by using the NLT (non-linear transformation) method, and 2 units of Kistler type 5233A dynamometer were used to measure ground reaction force. The sampling ratio was set at 1000 Hz. The golfers each took 10 swings by using their own driver, and chose the best and worse feel from among 10 shots. A paired-sample t-test was used to analyze the results. Results: In regard to feel, no change in head speed, X-factor, and the triple X-factor's X-factor stretch, hip rise, and head swivel, was observed (p>.05). Regarding ground reaction force, a difference was observed between the top of the backswing (p<.05) and impact (p<.05) in the vertical force of the left foot. For COP, a difference was also observed between the mid backswing (p<.001), late backswing (p<.001), and top of the backswing (p<.05) for the right foot X-axis and Y-axis mid follow through (p<.01). Conclusion: It can be reasoned that, irrespective of feel, the head speed, X-factor and triple X-factor's X-factor stretch, hip rise and head swivel did not have an effect on drive distance for domestic golfers, and the vertical reaction force of the left foot and left-right movement span's pressure dispersal of the right foot had an increasing effect on drive distance.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.79-94
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• 2005

Because the golf swing is very complex movement, it is varied in different gender, skill level, and club. This study measured kinematic variables in golf swing regarding gender, skill level, and club types using FasTrak electromagnetic tracking system. Golf swing kinematics including time variables, linear and angular displacement variables, angular velocity variables were analyzed and compared through three-way ANOVA The results were as follows: 1. In time variables, Female and driver showed longer backswing time than male and iron. Downswing time was longer in female and nonexperts than male and experts. Backswing time over downswing time was longer in experts than nonexperts. Uncocking time was longer in male and experts than female and nonexperts. The differences were statistically significant (p<.05). 2. In displacement variables, Female and nonexperts showed greater backswing head lift than male and experts. Impact head lift was greater in female, nonexperts, and iron than male, experts, and driver. The differences were statistically significant (p<.05). Experts and driver showed greater top hip rotation angle than nonexperts and iron. Top shoulder rotation angle was greater in male, experts and driver than female, nonexperts, and iron. X-factor was greater in male, experts, and driver than female, nonexperts, and iron. Male and experts showed greater backswing hip sway than female and nonexperts. Impact hip sway was greater in male and iron than female and driver. The differences were statistically significant (p<.05). 3. In velocity variables, Experts displayed higher impact hip rotation velocity than nonexperts. Impact shoulder rotation velocity was greater in male and iron than female and driver (p<.05).

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.97-104
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• 2005

Previous studies of kinematic analysis of golf swing usually dealt with variations vertically. The purpose of the study was to examine the horizontal hip joints motion of the fifteen male professional golfers during driver swinging. Kinematic variables were calculated by the Kwon3D motion analysis program. Paired t-tests and one-way ANOVA were used to compare the hip height, distance, displacement, and position differences. Results showed that there were no hip height changes and no hip height differences between left and right hip from address to impact. The axis of the backswing was braced right hip, the axis of the downswing was moving left hip. Hips position at the top of the backswing showed that hips move to target prior to hands, which means the sequential motion of the chain linked body segments. From address to impact, left hip moving distance was longer than right hip(p<.001), but during the whole swing, right hip moving distance was longer than left hip(p<.001). Hip rotation angle to target line was $-48.14{\pm}9.32^{\circ}$ at top of the backswing, $40.88{\pm}8.44^{\circ}$ at impact, and $104.70{\pm}8.14^{\circ}$ at finish.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.83-90
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• 2010

The purpose of this study is to validate that change of impact by the Early Extension in during a golf driver swing. 13 golf players who were diagnosed with symptoms of Early Extension participated in a proactive corrective training programs that took place 3 times a week for a 4 month period. Data was collected by recording 5 pre and 5 post training driver swings and analyzing the data to calculate the change in velocity and its effect in the shot used the TRACK MAN. After the training, the changes of early extension were -0.21 cm in backswing section E2(take away), -0.64 cm in E3(halfway backswing), and -0.94 cm in E4(backswing top). The downswing section changes were -1.34 cm in event E5(halfway downswing), -1.74 cm in E6(impact). Impact force increased and thus club speed increased by 6.32 km/h, ball speed increased by 10.94 km/h, max height decreased by -6.22 m, carry increased by 10.85 m, carry side(left deviation) decreased by 4.84 m, flight time by increased by 0.4 sec, and total length increased by 17.96 m while landing angle decreased by -7.74 deg.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.25-32
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• 2010

This study was performed to investigate the kinematic factors on the head hitting motion based on weight change of bamboo swords in kumdo. The kinematic factors, needed time per phase, COB displacement and velocity, angle(wrist, elbow, shoulder joint, hip joint, knee joint), were analyzed by the 3-D motion analysis method against 6 male middle school athletes. The results were as follows. 1. The needed time of head hitting motion based on weight change of bamboo swords was shorter when weight was heavier. 2. The COB displacement of left/right was bigger when weight was heavier. the displacement of right foot was higher at backswing phase and impact phase when weight was heavier and at impact time when weight was lighter. 3. The COB velocity was faster at impact time when weight was heavier, the velocity of sword tip was fastest for each event with bamboo sword weight of 440 g. 4. The angle of left elbow was smaller at top of backswing and impact when weight was heavier, the angle of left shoulder was bigger when weight was heavier, the right knee angle was biger at start when weight was heavier, at impact when weight was lighter.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.31-49
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• 2005

The purpose of this study was to analyze the weight transfer patterns under the different golf swing types which are full swing control swing and putting stroke. Two women golfers participated in this study, one(165cm, 94.3kg)being classified as a low-handicap(LH)player, the other(165cm, 54.5kg) being classified as a high-handicap(HH) player. Both players are right-handed. Two force plates(Kistler, 9286AA) were synchronized with a motion capture system(Qualisys ProReflex MCU240). Anteriorposterior, mediolateral, and vertical forces were used as an indicator of the pattern of swing. Four discrete positions which are address, top of backswing impact, and finish were identified as an event and three phases which are backswing downswing, and follow-through between he events were also identified. The results showed that, at impact, the total force was 1.24BW ring the full swing 1.17BW during the control stroke, 1.00BW during the putting stroke. Depending on the golf swing types, the differences are existed. At impact, the distribution of forces is different with a low-handicap(LH) player and a high-handicap(HH) player. A LH player has 26% in right foot and 74% in left foot during the full swing 49% in right foot and 51% in left foot during the control swing 49% in right foot and 51% in left foot during the putting stroke. A HH, on the other hand, has 74% in right foot and 26% in left foot during the full swing 62% in right foot and 38% in left foot during the control swing 54% in right foot and 46% in left foot during the putting stroke. From address to top of backswing the amount of vertical forces are changed 43:57(right foot: left foot) to 76:24 during the full swing 47:53(right foot: left foot) to 75:25 during the control swing 50:50(right foot: left foot) to 54:46 during the putting stroke. The biggest weight transfer pattern took place in full swing and the control swing is next, and the putting stroke is the final.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.789-796
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• 2019

The purpose of this study was to compare kinematic variables between elite golfer and novice during golf putting. 23 elite golfers and 19 novice were participated, and SAM Putt was used to collect kinematic variables. To identify main effect and interaction effect, it was performed Two-way Mixed ANOVA at a significant level of a .05. Elite and novice group, follow-through was significantly different and indicated main effect between distance and skill level. Impact, backswing, and loft angle were significantly different and showed main effect between skill level. Also, backswing rhythm and impact timing were significantly different and indicated main effect between skill level. Therefore, minimizing the movement of the wrist and keeping the putting strike rhythm may improve the putting ability.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.103-111
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• 2005

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.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.151-159
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• 2008

In this research, kinematic comparative analysis was performed on strokes of abscission and spinal cord injured athletes who participated in 2008 Beijing Paralympics wheelchair table tennis games. Strokes of all situations were collected under real match-like conditions. Among those, three major forehand stroke motions and backhand stroke motions were drawn Data collected by 9 infrared cameras were expressed in angular motions using graphic program LabVIEW7.0. As a result, forehand stroke of spin handicap athlete from analyzed images, the rotations of the trunk happened with the rotations of shoulder and the flexion extensions of elbow nearly at the same time. According to these results, insufficient turning force or speed of rackets is recompensed using flexion. backhand stroke of spin handicap athlete from analyzed images, the rotations of the trunk, the flexion extensions of the elbow and the flexion extensions of the shoulder were lined up on the prolongations of ping-pong balls. Forehand stroke of abscission athletes was done by outward rotation of the arm using backswing and inner rotation. As for backhand stroke, backswing was made by inner rotation in the spin of shoulder and waist. And after the backswing, impact was formed in wide outer rotation towards the ball.