• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.385-390
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• 2014

The purpose of this study was to investigate the effects of landing tasks on the anterior cruciate ligament (ACL) injury risk factors in female basketball players. Fifteen female basketball players performed a drop landing and a drop landing with a vertical jump on the 40 cm height box. Three-dimensional motion analysis system and ground reaction force system was used for calculate the ACL injury risk factors. Paired samples t-test with Bonfferoni correction were performed. The drop landing with a vertical jump had the higher knee flexion angle, peak knee varus moment, trunk flexion angle than a drop landing. However, the drop landing had the higher trunk rotation angle than a drop landing with a vertical jump. These results indicate that seemingly minor variations between drop landing and drop landing with a vertical jump may influence the ACL injury risk factors. Caution should be used when comparing studies using different landing tasks.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.219-223
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• 2013

The purpose of the study was to investigate the effects of gymnasts shoes on risk factors of anterior cruciate ligament injuries during drop-landing followed by vertical jump in female gymnasts. Thirteen female gymnasts were recruited and performed randomly drop-landing followed by vertical jump in height of her knee with and without shoes. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. Data were analyzed with paired samples t-test with Bonferroni correction. Female gymnasts with shoes showed more reduced thigh maximum adduction angle, and knee maximum extension moment than without shoes. Female gymnasts with shoes showed more increased shank maximum abduction angle than without shoes. In conclusion, Female gymnasts with shoes reduced anterior cruciate ligament injuries risk factors.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.115-120
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• 2010

Purpose : To separate and evaluate the low frequency spontaneous fluctuation BOLD signals from the functional magnetic resonance imaging data using sensorimotor active task. Materials and Methods : Twenty female archery players and twenty three control subjects were included in this study. Finger-tapping task consisted of three cycles of right finger tapping, with a subsequent 30 second rest. Blood oxygenation level-dependent (BOLD) data were collected using $T2^*$-weighted echo planar imaging at a 3.0 T scanner. A 3-D FSPGR T1-weighted images were used for structural reference. Image processing and statistical analyses were performed using SPM5 for active finger-tapping task and GIFT program was used for statistical analyses of low frequency spontaneous fluctuation BOLD signal. Results : Both groups showed the activation in the left primary motor cortex and supplemental motor area and in the right cerebellum for right finger-tapping task. ICA analysis using GIFT revealed independent components corresponding to contralateral and ipsilateral sensorimotor network and cognitive-related neural network. Conclusion : The current study demonstrated that the low frequency spontaneous fluctuation BOLD signals can be separated from the fMRI data using finger tapping paradigm. Also, it was found that these independent components correspond to spontaneous and coherent neural activity in the primary sensorimotor network and in the motor-cognitive network.

• Korean Journal of Biological Psychiatry
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• v.17 no.1
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• pp.37-43
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• 2010

Objectives : The $2^{nd}$ to $4^{th}$ digit length ratio(2D : 4D) is a sexually dimorphic trait regardless of ethnicity and shows sex differences. According to previous research, men usually have a relatively shorter $2^{nd}$ digit than $4^{th}$ digit. There is tendency that men with lower 2D : 4D are perceived as being more masculine and tend to perform better in some physical sports. Furthermore, 2D : 4D is negatively associated with trait aggression. In this study, we examine gender difference of 2D : 4D and compare 2D:4D of female Korean national team members to 2D : 4D of control subjects. Besides that, we also compare 2D : 4D of female Korean national team members according to their sports entries. Methods : The sample of this study is 396 people, 67 female Korean national team member, 216 control women and 113 control men. We measured $2^{nd}$ to $4^{th}$ digit length of their right hand. In addition, we collected demographic information of female Korean national team members using a self-report questionnaire. Results : The mean 2D : 4D of female Korean national team members is 0.96(SD=0.04), smaller than control women's 2D : 4D(0.97, SD=0.03) and significantly higher than control men's 2D : 4D(0.95, SD=0.03). We also found differences between control men and women. Non-martial arts related sports athletes have significant difference with control men in 2D : 4D. However, martial arts related sports athletes' 2D : 4D is not significantly different from other groups, including control men. Conclusion : These results are consistent with the findings of previous research that there is a significant difference between men and women in their 2D : 4D. Furthermore, 2D : 4D of martial arts related sports athletes have not shown any difference from the 2D : 4D of control men that 2D : 4D of non-martial arts related athletes have shown. This fact is important in consideration of masculine characteristics. For further research, it is necessary to examine 2D : 4D difference according to sport ability and gender differences.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.159-168
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• 2008

The purpose of this study was to analyze the variables of plantar pressure distribution, the COG between Flying Sit Spin(FSS) and Flying Camel Spin(FCS) during a Figure Skating. In order to investigate the two types of spin mechanism in the Korea national of elite women Figure skaters(N=4), this study investigated the phase time, CA(contact area), MF(maximum force) Mean Force, and PP(peak pressure) Mean Force. The data was collected using PEDAR Mobile System which is the pressure distribution measuring devices. The obtained conclusions were as follow: During the two types of spins(FSS and FCS), the FCS is higher than the FSS on the MF(20%BW), PP(20%BW) variables during P4 phase, but the FSS is larger than the FCS in the CA, MF, and PP during P1, P2, P3 phase. Consequently, depend on the COP and the COG locations about the vertical ground reaction vector, the FCS comparatively excelled control of speed feedback than the FSS in the P4 phase.

• Korean Journal of Applied Biomechanics
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• v.21 no.5
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• pp.661-667
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• 2011

The purpose of the study was to compare selected kinematic variables between the female medalists and a Korean female javelin thrower at the IAAF World Championships, Daegu 2011. Three medalists and one Korean javelin thrower that participated in the Championships were videotaped using three high-speed cameras (300 frames/s, EX-F1 Exilim, Casio, Japan). This study identified the performance differences between the two groups. The results showed that the Korean female javelin thrower (KFJT) clearly had a greater delivery phase time than the female medalists. In order to throw farther, a thrower must exert a greater force to accelerate their body in a short time. This study also found that the release velocity of the KFJT was lower than that of the female medalists. The KFJT showed evidence of using her extremities differently to achieve the maximum release velocity. When comparing the inclination angle of the trunk across javelin throwers, the lowest value was recorded in the KFJT. Because the trunk position at release plays a significant role in determining the release height and release velocity, the KFJT should not rely on her upper extremities to achieve as high a release velocity as possible.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.149-156
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• 2007

The purpose of this study was to compare the world class women's hurdlers with kinematic variables Lee Yeon-Kyoung's in the 100m hurdle. Among korea elite female hurdler, Lee Yeon-Kyoung was participated as a subject. Eight JVC video cameras(GR-HD1KR) were used to film the performance of Lee Yeon-Kyoung at a frame rate of 60fields/s. The real-life three-dimensional coordinate data of digitized body landmarks were smoothed using a fourth order Butterworth low pass recursive digital filter with an estimated optimum cutoff frequency of 7.4Hz. After analyzing and comparing Lee Yeon Kyung's kinematic variables with the world top class hurdlers in the woman's 100m hurdle run, the following conclusions were obtained. 1. Lee should be able to increase the speed with over 5.4m/s from start to first hurdle and then maintain the speed range from 8.33m/s to 8.67m/s until 10th hurdle. Lee should have to maintain the speed with 8.51m/s from 10th hurdle to finish line. 2. Lee has to reach her maximum running speed at 5th hurdle and then has to shorten running time with 0.5sec between hurdles. 3. Lee should be able to run around 2.5sec from start to frist hurdle and then maintain under 1.00sec following phases. Lee should be able to maintain under 1.10sec from 10th hurdle to finish line. 4. Lee needs to control a consistent takeoff and landing distance pattern, Lee needs to lower the height of the center of gravity of the body with 0.33m when she clears the hurdles.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.153-163
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• 2006

The purpose of this research was to analyze kinematic variables that appear during the instep shooting motion of female high school soccer players according to the angle of approach to find effective shooting motions. For this experiment, 5 female high school soccer players from the K city were participated in this study as the subject group, and as a through comparison and analysis of the resulting numbers of the variables, we came to the following conclusions. 1) Stride length and stride length/lower extremity length increased as the angle of approach increased. 2) As for C.O.G movement displacement, it was highest at an approach angle of $90^{\circ}$ during Right Foot Contact, at $135^{\circ}$ during Left Foot Contact, at $0^{\circ}$ during Rigth Toe Top, at $45^{\circ}$ during Impact, and at $0^{\circ}$ during Follow through. 3) The time required for each phase was longest at APP and shortest at BSP. The time required increased a little as the angle of approach increased, and the total time required also increased as the angle of approach increased. 4) The angle of the ankle joint was largest at an approach angle of $45^{\circ}$ for all events except Right Foot Contact. 5) The angle of the knee joint was largest at an approach angle of $135^{\circ}$ during Right Foot Contact, at $0^{\circ}$ during Left Foot Contact, at $45^{\circ}$ during Right Toe Top, at $135^{\circ}$ during Impact, and at $90^{\circ}$ during Follow through. 6) The angle of the hip joint was largest at an approach angle of $90^{\circ}$ during Right Foot Contact, at$0^{\circ}$ during Left Foot Contact, at $0^{\circ}$ during Right Toe Top, at $90^{\circ}$ during Impact, and at $0^{\circ}$ during Follow through.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.189-200
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• 2013

The purpose of this study was to compare the kinematic analyses of the women's pole vault skills difference between skilled group (1st to 8th place) and less skilled group (10th to 15th place) who participated in IAAF World Championships Daegu 2011. To achieve this goal, 16 women's pole vault player's kinematic analyses was conducted. Player's best performance was recorded by five normal video cameras operating at 60 Hz. The results of this study through the research procedures above are as follows. First, Skilled group's average step length and the ratio of step length to her height were longer than less skilled's group in run-up phase. Second, Skilled group's horizontal velocity was faster than less Skilled group's results. And pole plant angle was lower than less Skilled group's results in take-off phase. Third, Maximum pole flexion angle did not show difference of between two groups in pole bending phase. However, Skilled group's vertical velocity was higher than less skilled group's results.

• Journal of Nutrition and Health
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• v.32 no.7
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• pp.781-786
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• 1999

This study was designed to investigate the effects of vitamin E supplementation on radical scavenger activity and immune responses in female judo athletes(n=18). The age and sex matched sedentary students were used as controls(n=15). The initial plasma vitamin E concentration, lipid peroxide level and radical scavenger activity (RSA) were not different between two groups. The supplementation of $\alpha$-tocopheryl acetate(400IU/d) for 4 weeks significantly increased plasma vitamin E concentration of the subjects in both groups. In addition, the decrease in thiobarbituric acid reactive substance(TBARS)(p<0.05) and enhancement of RSA(p<0.05) were observed in both groups. Percentages of total T-cells in the athletic group was lower than that in the control group(p<0.05). However, the ratio of CD4 / CD8(helper T-cal $l^pressor T-cell) was higher in the sports group, due to more decrease in CD8 subset than in CD4 subset. The concentrations of IgG and IgM in the sports group were significantly lower than those in the control group(p<0.05). Therefore, severe training of the athletic group seems to be associated with the changes of supplementation. In conclusion, vitamin E supplementation (400IU/d, 4 weeks) of the female university students improved antioxidative activities of the blood, by decreasing lipid peroxide and enhancing radical scavenger activity. Percentages of T lymphocytes and IgG and IgM concentrations in the athletic group were lower than those in the control group. Meanwhile, vitamin E supplementation had no effects on immune status in both groups.ps.