• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.374-382
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• 2007

Robot mobility and intelligence become more important for robots to be used in various fields other than automation. The main purpose of providing mobility to a robot is to extend the robot's manipulability. In this paper, we introduce a small humanoid robot that can autonomously play golf as an example of incorporating robot intelligence, mobility, and manipulability. The robot has 12 degrees of freedom for legs and has various basic walking patterns. It can move to a desired position and change orientation by combining the basic waking patterns. The robot has a color CCD camera and can extract coordinates of the objects in the environments. The small humanoid robot has 8 degrees of freedom for arms and can play golf autonomously with two kinds of dexterous swing motions. Kinematic analysis of the robot arms, vision data processing for the recognition of the environments, algorithm for playing robotic golf have been performed or proposed. The experimental results show that the robot can play golf autonomously.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.75-82
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• 2012

The purpose of this study was to suggest the proper shaft and head fitting methods of the golf club to increase the flight distance of the golf ball. Rotations per minute of the golf ball(RPM), ratio of Ball speed to club head speed(T-Ratio) and launch angle right after impact(LA), which are directly related to ball flight distance, were measured using Spectra with shutter speed of 1/1000sec at the constant head speed of 95mph which was controlled by robot golf swing machine. In order to investigate the effect of club shaft to the 3 selected variables, 10 shafts were used to make ten test clubs with one controlled club head which is the most commonly used by golf players. To measure the effect of the club head to the 3 selected variables, 6 golf club heads which are most commonly used by golfers were selected to make 6 test clubs with a controlled shaft which is one of the best known by players. The shafts and the heads were identified by statistical analysis to increase or decrease the RPM, T-ratio and LA. A proper fitting method of the selected shafts and the club head was suggested to increase the ball flight distance in golf.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.2011-2014
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• 2005

The purpose of this study is to compare the modal parameters of a newly developed soft golf club prototype, which is designed to be lighter than regular golf clubs, with those of a regular commercial golf club. The modal tests were performed with two kinds of boundary conditions. The first condition was free-free condition and the second was fixed-free condition. An impact hammer and a Fast Fourier Transform analyzer were used to obtain modal data. From the results, it was found out that the modal characteristics of the soft golf club prototype were close to those of the regular golf club although the weight of the soft club was lighter. Therefore, the soft golf club is expected to be able to convey similar feel to the golfers even with lighter weight. This would enable elderly golfers to swing easily with the soft golf club with same skill which they acquired with regular golf clubs but with reduced load to their muscles.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.487-495
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• 2010

The purpose of this study was conducted to make a comparative biomechanical analysis of X-factor and X-factor stretch during driver and iron swing. The subjects were composed of 10 professional golfers with more than 10 years career. The result was as follows: First, the analysis of the back swing with driver and iron swing showed no differences statistically between both the timing in horizontal rotating of shoulder and hip, the time required for X-factor stretch also showed no differences statistically. Second, the back swing with a driver swing showed more maximum horizontal rotation of shoulder and hip joint than the back swing with an iron swing, but the twist of shoulder and hip that was X-factor stretch angle showed no difference. Third, the GRF of the max value for the left and right foot during shoulder and hip horizontal rotation of back swing showed no differences statistically in the movement of driver and iron swing during the back swing, and the GRF of X-factor stretch for the left and right foot showed no differences statistically in driver and iron swing. Therefore the result of this research showed that the operation of torso(X-factor stretch) and weight shifting were similar although the horizontal rotation of body was different during the driver and iron swing.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.15-21
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• 2004

Golf has become an increasingly a popular sports for young and older ages. It has benefits of walking exercise and enjoyment of sports . However, golf is considered to be a moderate risk activity for sports injury due to traumatic origin and overuse. Golf injuries primarily affect the dorsolumbar sites , upper extremity(elbow, shoulder, wrist) and lower extremity (knee, hip, ankle). Ajustment of golf swing and conditioning programmes for preventing injuries which include muscular strengthening, flexibility and a short pregame warm up help to reduce the incidence of injury.

• Korean Journal of Applied Biomechanics
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• v.21 no.4
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• pp.411-420
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• 2011

The purpose of this investigation was to determine whether correlations exist between balance and impact velocity, angular position, and maximum velocity of a club during drive swing. Twelve skilled golfers were recruited in this study. They were asked to perform ten swing trials and two trials were selected for analysis. Balance parameters were calculated via the force platform while kinematic variables were determined by using the Qualisys system. The results of the present study demonstrated that the average of COP velocity was faster in the medio-lateral direction rather than the anterio-posterior direction. Also, left foot's COP velocity and free torque were greater than the right foot's before impact. The range of the right foot's COP in the anterio-posterior direction before impact were correlated with the club velocity and angular position at impact. There was a negative correlation between the left foot's COP velocity before the impact and the velocity at impact. Additionally, the range and RMS of the left foot's free torque affected on the club angular position at impact and the maximum velocity at release, respectively. Finally, a negative correlation existed between the range of the right foot's free torque after the impact and club's maximum velocity at release.

• 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.

• The Journal of Korean Physical Therapy
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• v.34 no.4
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• pp.149-154
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• 2022

Purpose: The purpose of this study was to investigate effects of the modified bent arm tornado exercise on weight shift movement and muscle activity of the impact section in the top of the drive swing. Methods: Twenty subjects were divided professional golfer group and amateur golf group. Subjects were required to complete following modified bent arm tornado exercise. The activity and weight shift of the gluteus group and lower extremity muscles between the two groups were measured and the Wilcoxon rank test was analyzed. Results: The distribution of weight shift in the professional golfer group was higher than that of the amateur golfer group (p<0.05). During the golf downswing of the professional golfer group, muscle activation of the lower extremities was higher than that of the amateur golfer group (p<0.05). The distribution of weight shift after exercise by the amateur golfer group was higher than before (p<0.05). Conclusion: We could confirm was increased significantly of muscle activity and weight shift by applying modified bent arm tornado exercise through this study. This result suggests that exercise is needed to improve weight shift.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.273-286
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• 2009

The objective of this research is to evaluate both quantitative analysis and qualitative analysis by comparing vital variable factors of the golf swing successes and the failures. At the moment of swing, each body segment and the movement of the club as well as kinematical parameters were produced by utilizing the 3-D swing analysis for the high school female golfers. As kinematical parameters, it analyzes the 3-D analysis and ground reaction force about the location change, velocity and angle. The 3-D swing analysis and ground reaction force location change, velocity and angle are analyzed for Kinematical parameters. As a result, the stable swing is maintained by club head showing very few front-back movement (X) when the address and the top swing. Also, the center of mass velocity contributes to the momentum increase by showing very rapid velocity when successful comparing with when failed at the time of top swing of left-right(Y) and it is thought that by lessening the cocking angle when successful from the top swing to the impact, it influences the linear velocity increase and has a good effect on a non-distance increase. It shows that Ground reaction force (GRF) is examined by showing the stable approval rating in a front-back(X) direction and left-right(Y) and connected to a successful swing.

• 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.