• 한국체육학회지인문사회과학편
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• 제53권2호
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• pp.531-540
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• 2014

본 연구는 두 종류의 공기주입식 카약 보트의 성능 비교와 함께 선수들의 카약 전방 스트로크 동작의 차이점을 비교 분석하여 보다 효율적이고 안전한 카약 보트를 찾는 데 목적이 있다. 이를 위해 대한 체육회 소속 K 고등학교 엘리트 남자 선수 5명이 연구에 참여하였으며, K고 실내 수영장에서 실험을 실시하였다. 보트의 성능 평가를 위해 보트 속도, 보트 좌우 흔들림 각도 차이, 보트의 회전 평균 각속도를 산출하였으며 선수의 수행력 차이를 분석하기 위해 몸통의 회전 가동범위, 무릎 관절의 굴곡-신전 가동범위, 몸통의 최대 회전 각속도, 무릎관절의 최대 신전 각속도, 상하지 근육의 활성도를 산출하였다. 연구 결과 선수들의 수행력 평가 변인에서는 통계적으로 유의한 수치를 보이지 않았다. 보트의 성능 평가 변인에서는 보트의 속도에서 B보트가 통계적으로 유의하게 빨랐으며 다른 변인들은 통계적으로 유의한 차이를 보이지 않았다. 결국 길이가 상대적으로 길고 폭이 상대적으로 좁은 B보트는 A보트와 비교했을 때 비슷한 안전성을 갖고 있으면서 보다 효율성을 나타내었다.

• 한국운동역학회지
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• 제17권2호
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• pp.103-112
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• 2007

The purpose of this study was to investigate the kinematic characteristics during rising from a chair. Six stroke patients and three healthy subjects participated in the study. Three dimensional kinematic analysis was used to get the duration, center of mass, and lower extremity angle. The stroke patients performed longer duration(0.28sec) than the healthy subjects in rising from a chair. The stroke subjects stayed longer time than the healthy subjects did in phase 2(From the initiation of knee extension to the reversal of trunk flexion to trunk extension)(t=-1.01, p=.04). The healthy subjects showed longer time than the stroke subjects in phase 3(from the reversal of trunk motion to extension to full standing position). The healthy subjects displayed larger value of center of mass in anterioposterior direction than stroke subjects(t=5.79, p=0.05). The center of mass in the mediolateral direction did not change during the completion of movement. However, the center of mass in the anterioposterior direction began to increase throughout the completion of movement. The center of mass in the vertical direction increased extensively in phase 3. The significant difference was not found in the maximum dorsiflexion in ankle, the initiation angle of knee, and the minimum angle of hip between stroke and healthy subjects. Even though statistical results did not show any significant angle difference in the lower extremity, the patterns of the change in the knee and hip angle during rising from a chair were different. The stroke subjects showed smaller angle of knee extension than the healthy subjects in phase 3. The stroke subjects flexed their trunk more than the healthy subjects in phase 2.

• 대한물리의학회지
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• 제9권1호
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• pp.125-132
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• 2014

PURPOSE: This study aims to determine the optimal knee joint angle and hip joint angle for minimizing the cervical muscle tension and maximizing the muscle activity of the trunk during the bridging exercise for trunk stabilization. METHODS: The bridging exercise in this study included seven forms of exercise: having a knee joint flexion angle of $120^{\circ}$, $90^{\circ}$, $60^{\circ}$, $45^{\circ}$ and hip joint abduction angle of $15^{\circ}$, $10^{\circ}$, $5^{\circ}$. The posture of the bridging exercise was as follows. To prevent the increase of hyper lumbar lordosis during the bridging exercise, the exercise was practiced after maintaining the lumbar neutral position through the pelvic posterior tilting exercise. RESULTS: The abduction angles did not result in statistically significant effects on the cervical erector, external oblique, rectus abdominis and erector spinae muscles. However, in relation to the knee joint angles, during the bridging exercise, statistically significant results were exhibited. CONCLUSION: The knee joint angle affected the muscle activity of the neck muscle. The greater the knee joint angle, the lower the load placed on the neck muscle. In contrast, the load increased as the knee joint angle decreased. In addition, the muscle activity of the neck muscle and trunk muscle increased as the knee joint angle decreased.

• 한국운동역학회지
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• 제13권3호
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• pp.181-197
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• 2003

The Purpose of this study was to examine the kinematic analysis of the upper-limb motion of wheelchair basketball free throw shooting. Three-dimensional kinematic data were obtained from 8 male wheelchair basketball players performing a successful free throw. Players were divided into three groups, according to their IWBF classification(Group 1: 1 point players, Group 2: 2-2.5point players and Group 3:3.5-4 point players) Wheelchair basketball free throw motions were taken by video camera. The three-dimensional coordinates was processed by DLT. Players from Group 1 and 2 tended to release the ball from a lower height, with greater velocity and release angle. Players from Group 1 showed greater shoulder horizontal adduction and horizontal abduction angle, wrist ulnar flexion and radial flexion angle, and trunk angle. but players from Group 2 appeared lower shoulder abduction. Upper limb angular velocity showed most greatly in hands from Group 1, upperarm from Group 2, and forearm from Group 3.

• 한국식품영양학회지
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• 제18권2호
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• pp.127-134
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• 2005

This study was conducted to investigate the correlations among body composition, athletic ability and nutritional status according to BMI in Korean college students. The anthropometric measurements of three groups showed significant differences in weight, body fat, waist, hip, WHR, skinfold thickness(p<0.001). There were significant difference in vitamin A and niacin by their BMI(p<0.05). There were significant increase in trunk flexion(p<0.05) and maximal oxygen uptake(p<0.05) in subjects as their BMI. There were negative correlation between weight and foot balance, maximal oxygen uptake. Also, foot balance and maximal oxygen uptake were negatively related with BMI. There was a significant positive correlation between BMI and flexion(p<0.50). Grip strenth(p<0.01) and back strenth(p<0.05) were positively related with WHR. Overweight group was significantly inferior in muscular power and endurance but was better in muscular strength than the other groups. Based on this study, the further studies on obesity indice are required for health promotion among young women population.

• PNF and Movement
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• 제14권2호
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• pp.139-147
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• 2016

Purpose: This study examined whether a single application of a lumbar flexion muscle energy technique (MET) could significantly influence pain, functional status, and range of motion in chronic back pain patients with restricted active trunk flexion. Methods: Twenty volunteers were randomly assigned to either a control group or an experimental group. Ten subjects in the control group received no treatment. Ten subjects in the experimental group received five sessions with the muscle energy technique, five times per week for two weeks. Outcomes were measured before and after two weeks of treatment in both groups. Pain intensity was assessed using a visual analogue scale (VAS). Range of motion was measured using the sit-and-reach test (SRT). Functional disability levels were assessed using the Korean version of the Oswestry Disability Index (KODI). Results: The experimental group showed a significant difference in VAS, KODI, and SRT between pre- and post-treatment (p < .05), while the control group showed no significant changes. The changes in VAS, ODI, and SRT were statistically significant between the groups pre- and post-treatment (p < .05). Conclusion: This muscle energy technique is clinically effective for chronic low back pain patients.

• Clinics in Shoulder and Elbow
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• 제26권2호
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• pp.126-130
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• 2023

Background: Arm swing plays a role in gait by accommodating forward movement through trunk balance. This study evaluates the biomechanical characteristics of arm swing during gait. Methods: The study performed computational musculoskeletal modeling based on motion tracking in 15 participants without musculoskeletal or gait disorder. A three-dimensional (3D) motion tracking system using three Azure Kinect (Microsoft) modules was used to obtain information in the 3D location of shoulder and elbow joints. Computational modeling using AnyBody Modeling System was performed to calculate the joint moment and range of motion (ROM) during arm swing. Results: Mean ROM of the dominant elbow was 29.7°±10.2° and 14.2°±3.2° in flexion-extension and pronation-supination, respectively. Mean joint moment of the dominant elbow was 56.4±12.7 Nm, 25.6±5.2 Nm, and 19.8±4.6 Nm in flexion-extension, rotation, and abduction-adduction, respectively. Conclusions: The elbow bears the load created by gravity and muscle contracture in dynamic arm swing movement.

• 여성건강간호학회지
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• 제10권3호
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• pp.244-251
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• 2004

Purposes: This study was to examine the effects of postpartum exercise on pressure of the pelvic muscle contraction, body composition and physical fitness of postpartum mothers. Method: A nonequivalent pre-test, post-test control group study was conducted. Fifty-two postpartum mothers(experimental group, 26; control group, 26) admitted to a postpartum ward in a Busan mother-baby clinic were recruited. Data was analyzed using mean, $x^2$-test, and t-test by SPSS 10.0. Result: Body fat mass(t=-3.196. p= .002), body fat rate (t=-3.831, p= .000), and fat distribution(t=-3.026, p= .004) of body composition increased significantly in the experimental group after the postpartum exercise as compared with the control group. After an 8 week exercise program, the pressure of the pelvic muscle contraction in the experimental group was significantly higher than in the control group(t=3.329, p=.002). In the change of physical fitness, grip strength of the hand, back muscle strength, and trunk flexion forward were not significantly changed, but trunk backward extension in the experimental group significantly increased(t=1.950, p=.050). Conclusion: Postpartum exercise affects pelvic muscle contraction, body composition, and physical fitness of the postpartum mother.

• 대한산업공학회지
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• 제23권1호
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• pp.147-162
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• 1997

When designing workplaces or arranging controls on panel, devices and controls should be placed within the reach of operator's arm or foot to guarantee effective performances. Most of the existing research on the reach volume were based on measurements of a few subject's arm reach, and limited to Caucasian and Chinese populations. Furthermore, reach volume considering foot or trunk motion have not been investigated. Range of human joint motion and that of two degrees of freedom motion are needed to generate reach volume analytically using the sweeping algorithm. However, range of two degrees of freedom motion has not been measured up to now. Therefore, range of two degrees of freedom motion was measured in this research, where 47 college students were participated voluntarily as subjects. The results showed that the motion of one joint can be limited by the motion of another motion, that is to say, the shoulder flexion was decreased significantly when the shoulder was adducted or abducted. Second, new approximate algorithms generating reach volumes were suggested, in which range of two degrees of freedom motion was used as input data. Depending upon the body segment included such as trunk, arm and leg, three types of reach volume were provided, in which the human body was modeled as a multilink system based on the robot kinematics and the sweeping method was employed. Reach volume generated analytically in this study showed statistically reasonable results when compared with that obtained from direct measurement.

• 한국운동역학회지
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• 제17권4호
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• pp.73-82
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• 2007

The purpose of this study was to qualitatively analyze coordination pattern of joints and segments during Dwichagi in Taekwondo and present a point of difference as compared with the previous study on Dolryeochagi in Taekwondo. By the utilization of three-dimensional cinematography, the angles of individual joints and segments of six male Taekwondo experts during Dwichagi were calculated by using Euler's angle. The used coordination variables were angle vs. angle plots between adjacent joints and segments and angle vs. angular velocity plots of individual joints and segments, respectively. It was observed during Dwichagi that in-phase coordination and spring-like rotational control mechanism of the lower and upper trunk were transferred into straight spring-like control mechanism of lower leg passing through flexion-extension and the fixation of degree-of-freedom of lower trunk and hip joint alternatively. This comparative study that coordination variables were used seems to be more useful research direction to deeply understand basic control mechanisms of Taekwondo kicking techniques when compared with the previous studies that defined Dwichagi as a thrust movement pattern merely based on biomechanical variables of a kicking leg.