• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.159-171
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• 2012

The purpose of this study was to provide information about kinematic variables of the gliding and delivery motion of Hyung-Keun Lee, a high school shot putter who was ranked 1st at the 2011 National Sports Festivals. Three-Dimensional motion analysis using a system of 4 video cameras at a sampling frequency of 60 Hz was conducted during shot-putting events at the 2011 National Sports Festivals. During the gliding and delivery phase of the player the results showed following characteristics; 1) The gliding technique types of the player appeared to be the short-long technique as the gliding and stance length ratio were $42.3{\pm}3.87$ % and $57.7{\pm}3.87$ %, respectively. In addition, the trajectory of shots during the gliding and delivery phase showed different trajectory patterns with "S-shaped" type of elite players due to the deviation from a central axis of the APSS (athletic-plus shot system). 2) The horizontal velocity of COG made from gliding should maintain the velocity during transition and release phase, but the player showed a small momentum for a gradual decrease of velocity. 3) Therefore, the player requires to adjust an appropriate ratio between gliding and stance length with a strong muscle power at the trunk, throwing arm, and the lower extremity during gliding and delivery phase.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.63-74
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• 2005

J. R. PARK. The Analysis of Electrimyography and Kinematic of Kumdo Player's Head Hitting. Korean Journal of Sport Biomechanics, Vol. 15, No. 1, pp. 63-74, 2005. The purpose of this study were to describe and compare the selected electromyographical muscle activities of arm and kinematic data of kumdo player's head hitting. Using surface electrode electromyography, we evaluated muscle activity in 6 male players during head hitting motion. Surface electrodes were used to record the level of muscle activity in the carpi radialis, deltoid, triceps, biceps muscles during the player's head hitting. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The kumdo head hitting motion was divided into two phases: back swing, down swing. we observed patterns of arm muscle activity throughout two phases of the kumdo head hiting The results can be summarized as follows: right elbow angle had decreased and left deltoid muscle's activation had higher than right deltoid muscle's activation, right carpi radialis muscle's activation had higher than left carpi radialis muscle's activation in back swing phase, knee angle had decreased and left triceps muscle's activation had higher than right triceps muscle's activation, right deltoid muscle's activation had higher than left deltoid muscle's activation, right carpi radialis muscle's activation had higher than left carpi radialis muscle's activation in down swing phase

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.127-139
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• 2007

The purpose of this study was to examine the pitching ability of baseball player by analysing the effect of elastic resistance exercise and pilates exercise on EMG. Five out of currently active highschool baseball player performed 5 times a week of elastic resistance exercise and pilates for 8 weeks, each for 100 minutes. They demonstrated significant increase in EMG after 8 weeks of exercise. Especially, in extensor carpi radialis brevis and flexor carpi radialis of fore arm, they demonstrated significant increase of inning figure after exercise. These results suggested that elastic resistance exercise and pilates exercise can improve pitching ability of baseball player according to inning.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.161-171
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• 2011

The purpose of this study was to identify biomechanical characteristics of glide and delivery motion of In-Sung Hwang, player who is a member of the national team among the finalists in the men's shot put at the 2010 National Sports Festivals. Three-Dimensional motion analysis using a system of 3 video cameras at a sampling frequency of 60 Hz was performed for this study. During the glide and delivery phase the results showed following characteristics; 1) The glide type was suitable for the short-long technique, but the trajectory of shot at the glide and delivery phase showed a different trajectory pattern with "S-shaped" type of elite players due to many deviating from central axis of the APSS(athletic-plus shot system). 2) Left knee was more flexed during failed trials compared to successful trials but COG was higher. Therefore, the player showed less stability of COG as he may not get enough breaking force at the left foot. 3) Furthermore, it would be required to have strong muscle power at the trunk, throwing arm, and the lower extremity in order to achieve maintain a low projection angle of the release.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.201-208
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• 2013

The aim of this study was to investigate badminton smash and drop motion depends on player's level. To perform this study, ten male badminton players were participated: five skilled players (SG, age: $21.6{\pm}1.1$ yrs, height: $181.4{\pm}6.8$ cm, body mass: $72.4{\pm}5.7$ kg, career: $11.2{\pm}1.1$ yrs) and five less-skilled players (LSG, age: $21.2{\pm}1.1$ yrs, height: $180.2{\pm}5.6$ cm, body mass: $73.6{\pm}6.7$ kg, career: $10.6{\pm}0.9$ yrs). Three-dimensional motion analysis with 7 infrared cameras was performed with a sampling frequency as 200 Hz. Player's swing motion was divided into four events: starting motion (E1), backswing (E2), impact (E3), following (E4). For all upper joints, LSG showed greater angle differences between drop and smash motions than that of SG at E3 (p<.05). For all upper joints, greater angular velocities were found in SG than that of LSG. For both groups, significantly smaller angular velocities were found in drop motion than that of smash motion (p<.05). The greater sequential angular velocities (proximal to distal) were found in SG than LSG during smash motion. Based on our findings, performing the same motion between drop and smash would be related to enhance performance at badminton competition. It is expected that these results will be useful in developing a training program for enhancing performance of badminton athletes.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.97-108
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• 2006

C. H. OH, S. N. CHOI, T. G. NAM, The Kinematic Analysis of the Tennis Flat Serve Motion, Korean Jiurnal of Sports Biomechanics, Vol. 16, No. 2, pp. 97-108, 2006. By the comparison and the analysis of the different factors during the tennis flat serve motion such as the required time per section, the movement displacement of the racket, the velocity of the upper limbs joints, the physical center of gravity, and the angle and the angular velocity of the upper limbs joints between an ace player and a mediocre player, these following results were drawn. First, the experiment result of the total time required per section in a tennis flat serve motion showed that an ace player was faster than a mediocre player by 0.4 seconds. This result suggested that it was required to increase the speed of the racket head by a swift swing to perform an effective flat serve motion. Second, the experiment result of the movement displacement of the racket in the tennis flat serve motion showed that an ace player greatly moved toward the left side on an x-axis. But both an ace and a mediocre player were shown to be at the similar points on a y-axis at the moment of the impact of the racket. An ace player was also shown to be located at a higher position on a z-axis by 0.23m. Third, the velocity of the center of gravity of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fourth, the velocity of the upper limb joints of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fifth, the experiment result of the speed of the racket head in tennis flat serve motion showed that a mediocre player was faster than an ace player in the first phase, but the latter was faster than the former in the second, third, and the fourth phases. Sixth, at the moment of impact of a tennis flat serve, an ace player had greater flexion of the angle of the wrist joints by an 11.8 degree than a mediocre player. An ace player also had greater extension of the angle of the elbow joint and the shoulder joint respectively by a 5.2 degree and a 1.4 degree with a mediocre player. Seventh, an ace player had greater angular velocity of the upper limb joints and the hip joints than a mediocre player at the moment of the impact of tennis flat serve. Eighth, an ace player was shown to have a greater change of the forward and the backward inclination (or the anterior and posterior inclination) of the upper body

• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.183-191
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• 2012

The objective of this study was to evaluate the plantar foot pressure of skilled and unskilled players during a free throw. The experiment performed here in measured the movement route of the mean foot pressure, maximum foot pressure, and center of pressure in four event zones (ready, maximum knee flexion, release event, and maximum knee extension) for both groups while they were wearing the plantar foot pressure measurement equipment under identical conditions. The major findings are as follows. When getting ready (RD) during a free throw, the skilled player group had higher mean and maximum foot pressures, although neither variable showed significant differences statistically. For the maximum knee flexion (MF) during a free throw, the skilled player group had higher mean and maximum foot pressures, but only the mean foot pressure significantly differed statistically. For the release event (RE) during a free throw, the unskilled player group had higher mean and maximum foot pressures, but only the mean foot pressure significantly differed statistically. During the maximum knee extension (ME) of a free throw, the unskilled player group had a higher mean foot pressure, and the skilled player group had a higher maximum foot pressure. No significant correlation was found between the two groups. For the skilled player group, movement towards the center of pressure showed a stable form that moved from the rear to the front and from side to side during a free throw. For the unskilled player group, movement towards the center of pressure was unstable, which made it impossible to move from the rear to the front and from left to right.

• 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 Sport and Applied Science
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• v.5 no.2
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• pp.63-71
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• 2021

Purpose: The purpose of this study, we will evaluate and analyze the importance and performance of Seongnam Football Club visitors using IPA analysis to present new marketing strategies and improvement plans based on the basis of the audience's perception of the team's priority, low priority, and excessive effort. Research design, data, and methodology: In order to achieve the purpose of the study, the survey was conducted on 120 home spectators of Seongnam Football Club, and the analysis of the data was conducted using SPSS Window Version 21.0. Data were analyzed via frequency analysis, exploratory factor analysis, corresponding sample t-test, and IPA analysis. Findings are as follows. Results: First, the first quadrant showed 'The convenience of access to the stadium', 'Parking lot convenience', 'Tournament schedule guidance', 'Providing information about player', 'Providing information about the team', 'Ticket reservation method'. Second, the second quadrant showed 'Players' fan service', 'Cleanliness of toilets', 'A player's level of performance', 'Team's level of play', 'A match against a rival team'. Third, the third quadrant showed 'Indication of facility guidance', 'Seat comfort', 'Team's Star Player Possession', 'Various participation events', 'Gift recommendation'. Fourth, the fourth quadrant showed 'Player-related promotion through media', 'Promote match schedules through media', 'Entrance convenience', 'Ticket Price'. Conclusions: Based on these findings, Factor in first quadrant, fourth quadrant should be kept. On the other hand, factors in second quadrant should be improved as soon as possible while factors in third quadrant can be improved through new marketing strategies in the future. Future implications were discussed.

• 대한정형외과스포츠의학회:학술대회논문집
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• 2004.09a
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• pp.63-63
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• 2004