• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.35-41
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• 2021

The purpose of this study was to investigate the effect of prop exercise convergence using vibration on batting speed and batting accuracy in elementary school baseball players. Three times a week for six weeks. The vibration exercise experimental group and the control group were divided into each twenty members. The experimental group performed vibration convergence prop exercise, and the control group performed general exercise. Batting speed and Batting accuracy were measured. The experimental and control groups showed significant differences in the groups of batting speed before and after intervention. There was significant difference between the batting accuracy in the comparison between the experimental group and the control group. Prop convergence vibration exercise may help to improve the batting speed and batting accuracy of elementary school baseball players. In the future, adult and sport injury patient are needed.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.205-211
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• 2016

Purpose: The aim of this study was to analyze biomechanical factors and PMT (premotor time) of body muscles between elite college and amateur baseball players during the baseball batting motion. Method: Kinematic and electromyographic data were obtained for 10 elite college baseball players and 10 amateur baseball players who participated in this study. All motion capture data were collected at 200 Hz using 8 VICON cameras and the PMT of muscles was recorded using a Delsys Trigno wireless system. The peak mean bat speed and the peak mean angular velocities of trunk, pelvis, and bat with PMT of 16 body muscles were computed. These kinematic and PMT data of both groups were compared by independent t-tests (p < .05). Results: The pelvis, trunk, and bat showed a sequence of angular velocity value during baseball batting. The PMTs of right tibialis anterior, left gastrocnemius, external oblique, and erector spinae were significantly different between the two groups. Conclusion: The PMT of body muscles was related to the shifting of body and rotation of the pelvis and the trunk segment, and this action can be considered the coordinated muscle activity of the lower and upper body.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.277-284
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• 2012

The purpose of this study was to find out the changes in beginners' batting movements after taking undergraduate baseball lectures, by comparing and analyzing the speed of bat, the angle of body and its segments, the angular velocity and so on. For this purpose, the author picked up five undergraduates who had not taken baseball lectures, and conducted three-dimension computerized tomography twice on them, that is, before and after taking baseball classes, with eight infrared cameras and two force platforms. The conclusions are, first, the time required for swing was shortened after taking the classes. Second, the maximum velocity of the bat-end was increased. Third, at the time of impact, while the rotation angles of the pelvis and the tip of left foot were increased, the left elbow had more flexion after the classes. Fourth, the size of ground reaction force was increased at the point of swing where the ground reaction force of left foot became maximized. As we can infer from these conclusions, beginners' hitting movements before taking baseball classes tended to swing only with the arms, without waist rotation and weight shift of the lower body, but after the classes, their movements were proved to be corrected into the swing using the lower body. For the future studies, the author expects a research in a close to real environment by using pitching machine.

• Journal of the Korean Data and Information Science Society
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• v.25 no.2
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• pp.349-356
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• 2014

In baseball, sabermetric batting statistics are used to compare an offensive performance of players. There exist dozens of sabermetric statistics, but baseball fans don't like the complexity of an abundance of measures. This paper provides a batting grade index (BGI) using principal component based on eight batting statistics. These are OPS, ISO, SECA, TA, RC, RC/27, wOBA and XR. We show that how standardized batting statistics are aggregated and weighted to arrive at a single composite measure of BGI. Also our result allows for segmentation of players into groups using the K-means clustering algorithm.

• Korean Journal of Applied Biomechanics
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• v.13 no.1
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• pp.173-184
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• 2003

The purpose of this study was to investigate the batting characteristics in elite baseball players. Seven skilled collegiate players hit the ball which was thrown by a pitching machine linearly and strongly to the center of the field. Time, velocity, angle and pound reaction force variables were measured by using high-speed video cameras and pound reaction force analyzer. The results were as follows: 1. The elite players finished their stride performance in a short time and they stayed longer in a swing phase. The increases in the range of trunk rotation were associated with the delay of the swing phase. 2. The 'take-back' phenomenon in the trunk was showed after the stride phase. 3. The down swing demonstrated powerful line drives. 4. Equivalent body weights were placed on both feet during the ready phase. 95% of the body weights were moved to the rear foot during the stride phase, whereas the body weights were driven to the front foot during the swing phase. 95% of the body weights were placed on the front foot at impact.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.191-202
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• 2004

The batting performance in baseball is a repetitive movement. In order to make the stabilization of posture and the efficient shift of body weight, both the range of stance and stride are important. The previous studies explained that the consistent stride which included the amount of time, stance, and direction were needed. However, the batting performance is frequently changed according to the several speed of ball. Therefore, this study was to analyze the reaction time, the range of stance, the change of stride, and the change of GRF during the batting movement in three kinds of ball speed (120km/h, 130km/h, & 140km/h). Seven elite players are participated in this study. 1. The reaction time of the stride phase was short whereas the time of the swing phase was long according to the increasing ball speed. 2. The range of the stance was wide and the mediolateral direction of the stride was decreased according to the increasing ball speed. 3. In the three kinds of ball speed, the change of body weight was transferred to the center, the rear foot, and the front foot directions. The ball speed of 130km/h showed the high frequency of the suitable batting. At this ball speed, the movement of the body weight was shifted smoothly and the value of the Ground Reaction Force was large enough.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.41-47
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• 2019

In this paper, we propose a new batter evaluation model that reflects the skill of the opponent pitcher in Korean professional baseball. The model consists of evaluation factors such as Run Value, Contribution Score and Ball Consumption considering the pitcher grade. These evaluation factors are calculated as different data. In order to include the evaluation factors having different characteristics into one model, each evaluation factor is weighted and added. The genetic algorithms were used to calculate the weights, and the data were based on the 2016 records of Korea Professional Baseball and the salary data of the players of 2017. As a result of calculation of the weight, the weight of the Run Value was high and the weight of the Contribution Score was very low. This means that when calculating the annual salary, it reflects much of the expected score according to the batting result of the batter. On the other hand, the contribution score indicating the degree to which the batting result contributed to the victory of the team according to the state of the economy is not reflected in the salary or point system.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.539-549
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• 2008

Most important thing in professional baseball game among all kinds of sports is the winning. Both coaches and players collected and analyzed lots of game data to get a victory. In this paper, batting data are analyzed so as to represent informations of hitting direction visually. This method could be provided a lot of useful information about hitting direction of a specific batter or a team to not only coaches, players but also the audience.

• International Journal of Human Ecology
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• v.14 no.1
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• pp.41-55
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• 2013

The purpose of this study was to analyze human upper body surface changes at the shoulder and back area. The body surface data were analyzed in terms of muscle and bone displacement in dynamic postures. Body surface data were collected with a 3D body scanner. The body surface was scanned at the static and four baseball batting postures. The body surface dimensions over the deltoids, scapulae and trapezius were measured. The results show that the vertical measurements of the deltoids increased by 20%. The horizontal measurements of the axilla of the back increased. The surface of the trapezius was elongated by over 10%, and the lower back musculature was elongated by about 50%. The results of this study showed that changes in back body surface caused by upper arm movements. It was influenced by the deltoid articulated with the humeri and the scapulae and trapezius. These body surface changes caused by muscle activities and ranges of motion can be used to design functional clothing.

• 한국체육학회지인문사회과학편
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• v.55 no.6
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• pp.361-373
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• 2016

The winning rate is the most important indicator for running a professional baseball team because it directly affects the spectator. James(1980) suggests that the Pythagorean method is almost identical to the actual winning rate, which is known as a way of helping to establish a team strategy. In this study, it was analyzed what kind of detail difference produced difference between real winning rate and winning rate based on Pythagorean method for 10 years from 2005 to 2014. The purpose of this study is to derive a plan to improve the performance of Korean professional baseball team. The results show that the expected winning rate differs from the actual winning rate by +.062 to -.054. In the process of this result, records of base on balls of the hitter, strikeout of the hitter, base on balls of the pitcher, batting average, sacrifice fly, etc. were found to affect the performance of professional baseball team. Therefore professional baseball teams should improve their batting eye so they can get a base on balls and reduce strikeouts. In the case of a pitcher, it should be instructed to reduce the base on balls by improving the control.