달리기 시 일정한 속도에서 보폭 차이가 하지 관절의 3차원 힘과 모멘트에 미치는 영향

류지선 한국운동역학회 2002 한국운동역학회지 Vol.12 No.1

조도 변화가 여성노인의 보행 표준시간과 하지 관절파워에 미치는 영향

하종규 ( Chong Ku Hah ),이재훈 ( Jae Hoon Yi ),양정훈 ( Jeong Hoon Yang ),서욱현 ( Uk Hyeon Seo ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.2

The purpose of this study was to investigate walking standard time and joint powers of the lower extremities on the changes of illuminations in the elderly women. Ten older women (70.90±3.28 years, 154.70±3.47 cm, 53.80±5.39 kg) with normal vision and no gait disabilities participated in this study. All the experiments were performed on a level walkway from low to high lighting (six conditions). A 3-dimensional motion capturing system, force-plate, and EMG were used to acquire and analyze walking motion, force, and muscle activity data; the sampling frequency was 100 Hz, 1000 Hz and 1000 Hz respectively. To test the differences on walking standard time and joint powers of the lower extremities between the six lighting conditions, one-way repeated ANOVAs were evaluated. The following results were drawn: First, mean standard time was about 1.3 sec/stride, and velocities were smaller with lighting increasing except 100 Lx. Second, the joint power patterns of ankle and knee were not consistent, but only hip joint power was a greatest in 6 Lx and a smallest in 400 Lx. Third, standard times(100 Lx<300 Lx, 400 Lx) were statistically significant, and hip joint max powers (100 Lx>others) were also statistically significant. But ankle and knee joint max power were not statistically significant. These results showed that standard times from low to high lighting were not consistent, and hip joint of 100 Lx has a greatest rotational torque. We suggested that gait strategies of them as to changing illuminations were not consistent and findings may represent a lack of adaptability in the elderly women.

아동의 복합운동이 착지 시 하지 손상요인에 미치는 영향

하성희 ( Sung He Ha ),류시현 ( Si Hyun Yoo ),김주년 ( Joo Nyeon Kim ),길호종 ( Ho Jong Gil ),류지선 ( Ji Seon Ryu ),윤석훈 ( Suk Hoon Yoon ),박상균 ( Sang Kyoon Park ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.2

The purpose of this study was to investigate the effect of combined exercise on injury risk factors of lower extremity during landing. Ten sports talented athletes participated in this study. Sports talented athletes participated in a combined exercise (sports talented exercise, coordination) for 16 weeks. A three-dimensional motion analysis was performed using eight infrared cameras (sampling rate of 100 Hz), one force plate, and electromyography system (sampling rate of 1000 Hz) during landing. Kinetic, and kinematics analysis including average impulsive force, angle of lower extremity, vertical stiffness, onset of muscle activation were calculated by Matlab2009a software. Paired t-test was performed at alpha=.05. The average impulsive force in landing phase was not statistically significant (t=-.748, p=.474). The hip joint angle was more decreased in post test compared to pre test (E1: t=2.682, p=.025, E2: t=5.609, p=.000, E3: t=2.538, p=.032). The knee joint (E1: t=-.343, p=.739, E2: t=1.319, p=.220, E3: t=.589, p=.570) and ankle joint (E1: t=.081, p=.937, E2: t=.784, p=.453, E3: t=.392, p=.704) angle were tended to decrease after combined exercise. The vertical stiffness was tended to decrease after combined exercise (t=1.972, p=.080). Onset of quadriceps femoris (t=.698, p=.503) and medial gastocnemius (t=1.858, p=.096) were tended to be faster than biceps femoris (t=-.333, p=.747) after combined exercise. Although thses findings were not statistically significant except on a hip joint angle, risk factors of lower extremity such as joint angle, vertical stiffness and onset of quadriceps femoris, medial gastrocnemius were positively changed after the combined exercise but an additional training for improved onset of biceps femoris would be required in the future.

단신 : 페달링 시 정량적인 동적 피팅을 위한 실시간 평가 시스템

이주학 ( Joo Hack Lee ),강동원 ( Dong Won Kang ),배재혁 ( Jae Hyuk Bae ),신윤호 ( Yoon Ho Shin ),최진승 ( Jin Seung Choi ),탁계래 ( Gye Rae Tack ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.2

In this study, a real-time evaluation system for quantitative dynamic fitting during pedaling was developed. The system is consisted of LED markers, a digital camera connected to a computer and a marker detecting program. LED markers are attached to hip, knee, ankle joint and fifth metatarsal in the sagittal plane. Playstation3 eye which is selected as a main digital camera in this paper has many merits for using motion capture, such as high FPS (Frame per second) about 180FPS, 320×240 resolution, and low-cost with easy to use. The maker detecting program was made by using Labview2010 with Vision builder. The program was made up of three parts, image acquisition & processing, marker detection & joint angle calculation, and output section. The digital camera`s image was acquired in 95FPS, and the program was set-up to measure the lower-joint angle in real-time, providing the user as a graph, and allowing to save it as a test file. The system was verified by pedalling at three saddle heights (knee angle: 25, 35, 45o) and three cadences (30, 60, 90 rpm) at each saddle heights by using Holmes method, a method of measuring lower limbs angle, to determine the saddle height. The result has shown low average error and strong correlation of the system, respectively, 1.18±0.44o, 0.99±0.01o. There was little error due to the changes in the saddle height but absolute error occurred by cadence. Considering the average error is approximately 1°, it is a suitable system for quantitative dynamic fitting evaluation. It is necessary to decrease error by using two digital camera with frontal and sagittal plane in future study.

체감형 스키 시뮬레이터 개발을 위한 플루크보겐 동작의 운동역학적 비교

구도훈 ( Do Hoon Koo ),이민현 ( Min Hyeon Lee ),권효순 ( Hyo Sun Kweon ),현보람 ( Bo Ram Hyun ),은선덕 ( Seon Deok Eun ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.3

The purpose of this study was to compare pflugbogen``s biomechanical characteristics between on the ski simulator and snowed ski slope to develop interactive ski simulator. Nine ski instructors(sex: male, age: 29.6±5.4 yrs, height: 176.0±5.6 cm, body mass: 76.0±14.0 kg) belong to Korean Ski Instructors Association participated in this research. 24 Infrared cameras for snowed ski slope experiment and 13 infrared camera for ski simulator experiment were installed near by path of pflugbogen. The participants did pflugbogen on the snowed ski slope and the ski simulator both. During the experiment, the participants weared motion capture suit with infrared reflective makers on it, and plantar pressure sensors in ski boots, so that ski motion and plantar pressure data were collected together. Displacement of COG(center of gravity) movements, trunk flexion/extension angle, adduction/abduction angle, and plantar pressure data were significantly different between on the simulator and ski slope. However, percentage of time of COG movement in the phases during medial/lateral and anterior/posterior movement were not significantly different. Findings indicate that the difference between two groups occurred because the ski simulator``s drive mechanism is different from ski motion on the slope. In order to develop the ski simulator more interactively for pflugbogen, the ski simulator``s drive mechanism need to be reflected 3D motion data of pflugbogen on the slope that were purposed in this research.

알파인 스킹 시 카빙 턴과 베이직 패러렐 턴 간의 신체중심 및 하지관절의 운동학적 패턴 비교

김주년 ( Joo Nyeon Kim ),전현민 ( Hyun Min Jeon ),류시현 ( Si Hyun Yoo ),하성희 ( Sung He Ha ),김진해 ( Jin Hae Kim ),류지선 ( Ji Seon Ryu ),박상균 ( Sang Kyoon Park ),윤석훈 ( Suk Hoon Yoon ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.3

This study investigated the center of mass and lower extremity kinematic patterns between carved and basic paralell turn during alpine skiing. Six experienced skiers (age: 20.67±4.72 yrs, body mass: 72.67±7.15 kg, height: 171.00±5.51 cm) participated in this study. Each skier were asked to perform carved and basic paralell turn on a 22.95° groomed slope. Each turn was divided into the initiation phase, steering phase 1 and 2. The results of this study show that the carved turn spent significantly less running time than basic paralell turn at all three phases (p<.05). Also vertical displacement of the center of mass was significantly greater in carved turn at all three phases, whereas inward leaning angle of the center of mass was significantly greater in carved turn at the steering phase 1 and 2 (p<.05). Bilateral knee and hip joint angle were significantly greater in basic paralell turn at the initiation phase and the steering phase 2 (p<.05). On the other hand, left knee and hip joint angle were significantly greater in basic paralell turn at the steering phase 1 (p<.05). In order to perform successful carved turn, we suggest that skiers should coordinate bilateral knee and hip joint angles to adjust the center of mass, depending on three ski turn phases.

시각 반응에 대한 악력과 EMG 신호의 평가

신성욱 ( Sung Wook Shin ),정성훈 ( Sung Hoon Jeong ),정성택 ( Sung Taek Chung ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.2

Hand grip strength has been utilized as an indicator to evaluate the motor ability of hands, responsible for performing multiple body functions. It is however difficult to evaluate other factors (other than hand muscular strength) utilizing the hand grip strength only. The purpose of this study was analyzed the motor ability of hands using EMG and the hand grip strength, simultaneously in order to evaluate concentration, muscular strength reaction time, instantaneous muscular strength change, and agility in response to visual reaction. In results, the average time (and their standard deviations) of muscular strength reaction EMG signal and hand grip strength was found to be 209.6±56.2 ms and 354.3±54.6 ms, respectively. In addition, the onset time which represents acceleration time to reach 90% of maximum hand grip strength, was 382.9 ± 129.9 ms. Results in visual reaction (on) indicate the differences in muscular strength agility and concentration of participants in regards to visual reaction.

8주 동안의 육상 교양수업 참여가 단거리 스타트 동작에 미치는 영향

이진택 ( Jin Taek Lee ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.3

The purpose of this study was to explore the effect of 8 weeks after school classes of track sports on students`` start motion through kinematic variables. 30 students in D National university of education participated for this study. These students divided into two groups, 17 students for experimental group and 13 students for control group. The two groups participated in general athletic class as common class, and the experimental group participated in after school class additionally. The general class taught track and jump skill for 3 hours a week, and the after school class taught only athletic running skill for 30 minutes a week. Pre and post test assessed to assess students’ kinematic changes. Findings indicated that velocity and step rate were increased, and contact time, step length, displacement of center of mass were decreased in the experimental group. In the control group, early velocity, knee/hip angle velocity were increased, and contact time, step length, displacement of center of mass were decreased. In conclusion, the students who only participated in general class, could not maintain athletic skills obtained from the class. However, students who participated in both general and after school class accomplish athletic start skill. This is because Continuous learning effect helped students keep the skill and did not lose the skill. Thus, in order for students to learn specific sport skills, joining after school class with general class together is recommended.

주의초점 전략이 태권도 기본동작의 속도 및 분절 협응패턴에 미치는 효과

강성철 ( Sung Chul Kang ),김기태 ( Ki Tae Kim ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.3

This study comparatively analyzed the speed and segment coordination characteristics of Taekwondo hand techniques, while different attention focusing strategies were utilized. Ten elite Taekwondo poomsae athletes participated, and three different strategies (no focus, target focus, body focus) were utilized in random order. The hand velocity and upper body segment coordination characteristics were analyzed, with the following results. First, the maximum magnitudes of the hand velocity differed between the focus conditions for the Araenaereomakgi and Momtongjireugi techniques. Second, the angular velocity and kinetic energy transfer patterns of the segments differed between the focus conditions, and in the case of the body focus condition, the movement was more correct according to the theory. Third, the shoulder and elbow joint coordination patterns differed between the focus conditions, with more efficient movement shown with the body focus condition. In conclusion, we confirmed the potential of effectively using an attention focusing strategy in a taekwondo teaching situation. However, the effect on the movement coordination and results of the movement could be changed by a difference in the cue provided or the type of the task. In addition, depending on the task, the attention focusing strategy could affect the efficiency of the movement. Therefore, coaches and masters of Taekwondo will have to constitute determine the appropriate attention focusing cues based on the task.

석문일월무예 음양보법의 숙련성에 따른 보행 패턴의 하지 운동학 및 운동역학적 특성

박복희 ( Bok Hee Park ),김기형 ( Ky Hyoung Kim ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.3

The purpose of this study was to quantify kinematic and kinetic characteristics of Yin-yang Bo gait according to their motor expertise, one of the Seokmun Ilwol martial art gait patterns. Yin-yang Bo gait pattern shows initial forefoot contact instead of heel contact, and increased time of stance phase time, internal-external rotation of ankle-knee-hip joints and pelvic. It aims to produce and store the more energy through continuous homeostasis of center of gravity (COG) and performance of stretch-shortening cycle. Some of these characteristics also were similar to the gait modification strategies for reducing knee adduction moment such as toe-out progression, medial thrust, internal rotation of hip joint. To identify the characteristics, four factors of expert Yin_yang Bo gait performance group were compared to that of none expert group; 1) angles of COG displacement and rotation 2) distal joint pre-rotation in internal-external rotation of ankle-knee-hip joints and pelvic, 3) invariability pelvic potential and pelvic segment total energy 4) knee abduction moment. Six healthy(three male) subjects participated in the experiment to perform Yin-yang gait pattern. Three-dimensional and force plate data were collected. Kinematic and kinetic data were compared between two groups using t-tests. Results showed that 1) the peak point of COG internal rotation angle was reduced in expert group, 2) kneeexternal and hip joint -internal and pelvic rotation angle peak frames were more near points in expert group.