• 한국전문물리치료학회지
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• 제25권3호
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• pp.19-26
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• 2018

Background: Genu varum is also known as bow leg. It is a deformity wherein there is lateral bowing of the legs at the knee. it does give rise to pain, and persistent bowing can often give rise to discomfort in knees, hips and ankles. Objects: This study investigated the effect of narrow squats on the knee joint during a gait and distance between the knees of person with genu varum. Methods: This study analyzed 23 patient with genu varum that grade III, 12 narrow squat group and 11 genenal squat group in motion analysis laboratory. The subjects of experiment took gait before and after intervention, the range of joint motion, moment of knee joint adduction, power, distance of the knees were measured. And in order to make an analysis between groups, an paiered t-test and independent t-test was carried out. For statistical significance testing, it was decided that significance level ${\alpha}$ be .05. Results: It was shown that the group of narrow squat exercise significantly decreased in distance of knees (p<.05),In moment of adduction of knee joint, it was shown to significantly decrease in two groups (p<.05), was significantly decreased in adduction, abduction, and rotation (p<.05). In relation of peak-knee adduction moment and valgus angle, there was significant decrease in narrow squat group (p<.05). Conclusion: When the above result of study were examined, a narrow squat exercise given to the genu varum patients significantly decreased the distance between the knees, range of knee adduction and abduction, knee adduction moment, knee power. And stability gains through the decrease of excursion of knee medial part be effective for the correction of genu varum deformation.

• 한국운동역학회지
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• 제24권2호
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• pp.173-180
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• 2014

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.

• 한국운동역학회지
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• 제31권4호
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• pp.308-313
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• 2021

Objective: The purpose of this study was to investigate the effect of different kettlebell mass (30%, 40%, and 50% of the body mass) on kinematics and kinetic variables of kettlebell swing. Method: Total of 16 healthy male who had at least 1 year of kettlebell training experience were participated in this study (age: 31.69 ± 3.46 yrd., height: 173.38 ± 4.84 cm, body mass: 74.53 ± 6.45 kg). In this study, a 13-segments whole-body model (upper trunk, lower trunk, pelvis, both side of forearm, upperarm, thigh, and shank) was used and 26 reflective markers were attached to the body to identify the segments during the movement. A 3-dimensional motion analysis with 8 infrared cameras and 4 channeled EMG was performed to find the effect of kettlebell mass on its swing. To verify the kettlebell mass effect, a one-way ANOVA with a repeated measure was used and the statistical significance level was set at 𝛼=.05. Results: Firstly, in all lower extremity joints and thoracic vertebrae, a statistically significant change in angle was shown according to an increase in kettlebell mass during kettlebell swing (p<.05). Secondly, in both the up-swing and down-swing phases, the knee joint and ankle joint ROM showed a statistically significant increase as the kettlebell mass increased (p<.05) but no statistically significant difference was found in the hip joint and thoracic spine (p>.05). Lastly, the hamstrings muscle activity was statistically significantly increased as the kettlebell mass increased during up-swing phases (p<.05). Also, as the kettlebell mass increased in P4 of the down swing phase, the gluteus maximus showed a statistically significantly increased muscle activation, whereas the rectus femoris showed a statistically significantly decreased muscle activation (p <.05). Conclusion: As a result of this study, hip extension decreased and knee extension increased at 40% and 50% of body mass, and the spine also failed to maintain neutrality and increased flexion. Also, when kettlebell swings are performed with 50% of body mass, synergistic muscle dominance appears over 30% and 40% of body mass, which is judged to have a risk of potential injury. Therefore, it is thought that for beginners who start kettlebell exercise, swing practice should be performed with 30% of body mass. In addition, even in the case of experienced seniors, as the weight increases, the potential injury risk may increase, so it is thought that caution should be exercised when performing swings with 40% and 50% of body mass. In conclusion, it is thought that increasing the weight after sufficiently training with 30% of the weight of all subjects performing kettlebell swing is a way to maximize the exercise effect as well as prevent injury.

• 천문학회보
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• 제46권2호
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• pp.38.2-39
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• 2021

I will presents the analysis of the gas properties of the protoplanetary disk surrounding the young low-mass (about 1.2M_sun) triple star, GG Tau A. This work makes use of ALMA observations of rotational lines of CO (¹²CO, ¹³CO and C¹⁸O) together NOEMA observations of a few dozens of other molecules. While the CO emission gives information on the molecular layer close to the disk atmosphere, its less abundant isotopologues ¹³CO and C¹⁸O bring information much deeper in the molecular layer. I will present the analysis of the morphology and kinematics of the gas disk using the CO isotopologues. A radiative transfer model of the ring in CO isotopologues will also be presented. The subtraction of this model from the original data reveals the weak emission of the molecular gas lying inside the cavity. Thus, I am able to evaluate the properties of the gas inside the cavity, such as the gas dynamics, excitation conditions, and the amount of mass in the cavity. High angular resolution observations of CO reveals sprials induced by embedded planet(s) located near the 3:2:1 mean-motion resonance that help to explain the special morphology of the circumbinary disk. I also discuss some chemical properties of the GG Tau A disk. I report the first detection of H2S and C₂S in a protoplanetary disk. The molecule abundance relative to ¹³CO of about twenties other molecules will also be given. In GG Tau A, the detections of rare molecules such as H₂S and C₂S have been probably possible because the disk is more massive (a factor about 3-5) than other disks where the molecules was searched. Such a large disk mass makes the system suitable to detect rare molecules and to study cold-chemistry in protoplanetary disks.

• 자원환경지질
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• 제56권3호
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• pp.293-300
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• 2023

Shape Preferred Orientation (SPO) 분석법은 단층의 운동학적 연구에 기초자료로 사용되는 단층면 운동 방향 분석을 위해 사용할 수 있는 방법으로 이용되어왔다. 단층비지 내 석영, 장석 등의 암편들로 이루어진 강성체들은 주어진 전단력에 의해 강성체 회전을 통해 P-전단 방향으로 배열되며, 이 특성을 이용해 역으로 SPO로부터 단층 운동 방향을 추정할 수 있다. 최근 X-선 CT 영상을 활용해 3D-SPO를 측정하여 빠른시간 내에 다수의 입자들의 형태를 조사함으로서 정밀도와 신뢰성을 확보하는 방법이 개발되었다. 이로서 SPO 분석법은 수천~수만개 이상의 입자들의 방향성을 빠른 속도로 분석하여 단층 운동 방향을 제시하며 용이한 접근성과 신뢰도 높은 데이터를 제공한다. 더불어 SPO 분석과정에서 획득되는 부산물인 입자들의 형태학적 정보와 방향성 분포 데이터는 단층 활동 당시 일어난 단층암의 국부적 변형, 단층 발생 메커니즘과 같은 다양한 연구를 진행할 수 있는 기초데이터로서 활용 할 수 있을 것으로 기대된다.

• 한국전문물리치료학회지
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• 제20권1호
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• pp.64-73
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• 2013

The purposes of this study were to develop a new orthosis controlling ankle and knee joint motion during the gait cycle and to identify the effects of the newly designed orthosis on gait kinematics and tempospatial parameters, including coordination of the extremities in stroke patients. Fifteen individuals who had sustained a stroke, onset was 16 months, participated in this study. Before application of the measurement equipment the subjects were accustomed to walking on the ankle-foot orthosis (AFO) or stance control knee with knee flexion assisted-oil damper ankle-foot orthosis (SCKAFO) for 5 minutes. Fifteen patients were investigated for 45 days with a 3-day interval between sessions. Measurements were walking in fifteen stroke with hemiparesis on the 3D motion analysis system. Comparison of AFO and SCKAFO are gait pattern. The difference between the AFO and SCKAFO conditions was significant in the gait velocity, step length of the right affected side, stance time of both legs, step-length asymmetry ratio, single-support-time asymmetry ratio, ${\phi}$-thigh angle and ${\phi}$-shank angle in the mid swing (p<.001). Using a SCKAFO in stroke patients has shown similar to normal walking speeds can be attained for walking efficiency and is therefore desirable. In this study, the support time of the affected leg with the SCKAFO was longer than with the AFO and the asymmetry ratio of single support time decreased by more than with the AFO. This indicates that the SCKAFO was effective for improving gait symmetry, single-support-time symmetry. This may be due to the decrease of gait asymmetry. Thus, the newly designed SCKAFO may be useful for promoting gait performance by improving the coordination of the extremity and decreasing gait asymmetry in chronic stroke patients.

• 한국운동역학회지
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• 제27권3호
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• pp.197-203
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• 2017

Objective: The purpose of this study was to determine how exercise intensity affects muscle activity and kinematic variables during squat. Method: Fifteen trainers with >5 years of experience were recruited. For the electromyography (EMG) measurements, four surface electrodes were attached to both sides of the lower extremity to monitor the rectus femoris (RF) and biceps femoris. Three digital camcorders were used to obtain three-dimensional kinematics of the body. Each subject performed a squat in different conditions (40% one-repetition maximum [40%1RM], 60%1RM, and 80%1RM). For each trial being analyzed, three critical instants and two phases were identified from the video recording. For each dependent variable, one-way analysis of variance with repeated measures was used to determine whether there were significant differences among the three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: The results showed that the average integrated EMG values of the RF were significantly greater in 80%1RM than in 40%1RM during the extension phase. The temporal parameter was significantly longer in 80%1RM than in 40%1RM and 60%1RM during the extension phase. The joint angle of the knee was significantly greater in 80%1RM than in 40%1RM at flexion. The range of motion of the knee was significantly less in 80%1RM than in 40%1RM and 60%1RM during the flexion phase and the extension phase. The angular velocity was significantly less in 80%1RM than in 40%1RM and 60%1RM during the extension phase. Conclusion: Generally, the increase of muscle strength decreases the pace of motion based on the relation between the strength and speed of muscle. In this study, we also found that the increase of exercise intensity may contribute to the increase of the muscle activity of the RF and the running time in the extension phase during squat motion. We observed that increased exercise intensity may hinder the regulation of the range of motion and joint angle. It is suitable to perform consistent movements while controlling the proper range of motion to maximize the benefit of resistance training.

• 한국항해항만학회지
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• 제39권3호
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• pp.253-260
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• 2015

열악한 작업환경 때문에 수중항만공사를 기계화하려는 많은 노력들이 시도되고 있다. 본 논문은 수중항만공사 중 사석 고르기 작업을 수행하는 수중건설로봇에 대해 기술한다. 로봇의 블레이드는 울퉁불퉁한 지형에서도 사석 마운드를 기준면에 대해 평편하게 고르고, 다목적암은 사석을 파고, 채울 수 있게 설계되었다. 본 연구는 로봇에 설치된 위치 및 방위 센서와 동기를 이루면서 주행과 스윙운동이 포함된 다목적암과 블레이드의 기구학을 해석한다. 기준수심센서에 부여된 월드좌표에 대해서 블레이드와 다목적암의 위치와 방위를 나타내고, 기준면과 나란한 고르기 작업을 위한 형상을 찾는다. 고르기 작업을 위한 유압제어시스템을 개발하며, 로봇에 의한 육상 및 수중 사석 고르기 작업을 실시해 실험결과를 보인다. 로봇의 작업속도는 잠수부보다 8배 정도 빠르며 작업품질도 우수한 것으로 평가된다. 잠수부가 작업할 수 없는 대수심에서는 효율성이 더 좋을 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제20권4호
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• pp.479-484
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• 1999

본 연구에서는 사람의 턱 운동과 턱 사이에 작용하는 힘(혹은 압력)을 그대로 나타낼 수 있는 저작로봇을 개발하는 것을 궁극적인 목표로 한다. 이러한 저작로봇이 개발되면, 치과의사가 환자의 턱운동에 나타나는 병변을 진단하고 치료하는데 큰 도움이 될 것으로 사료된다. 또한 , 본 연구에 채택한 병렬기구(parallel mechanism)에대한 순기구학적( forward kinematics)분석은 일반적인 병렬기구의 실계에도 응용될 것으로 기대된다. 본 연구진이 1차적으로 설계한 모델은 베이스와 플랫폼(platform), 그리고 이 둘을 연결하는 3개의 다리로 구성되어 있다. 다리와 플랫폼은 3자유도의 관절로 다리와 베이스는 1자유도의 경첩 관절로 연결되어 있으며, 이 3개의 경첩 관절은 베이스 위의 수평면에서 직선을 따라 움직인다. 경첩 관절의 수평 변위와 세 다리의 길이가 주어졌을 때 플랫폼의 위치와 오리엔테이션을 구하는 순기구학의 해( 解)를 계산해내는 알고리즘을 개발하였다. 이 알고리즘의 특징은 매 순간 오차를 계산하여 이 오차가 줄어드는 방향으로 나아가도록 시간간격(time step)을 조절하는 것이다. 본 알고리즘은 현재 가장 보편적으로 사용되고 있는 뉴튼-렙슨 방법에 비하여 3가지 장점을 나타내고 있다. 우선 , 초기치(initial guess)에 관계없이 수렴한다는 것이다. 또한, 본 알고리즘은 뉴튼-렙슨 방법에 비하여 수렴속도가 훨씬 빠르며, 연산 시간이 매우 짧아져 실제적인 실시간 적용에 적합하다. 마지막으로, 뉴튼-렙슨 방법에서는 여러 개의 해 가운데 어느 곳으로 수렴할 지 예측 할수 없으나 본 알고리즘에서는 초기치에 가장 가까운 해로 수렴한다. 이러한 순기구학의 다중성(multiplicity)문제를 해결하기 위하여 두 개의 조건을 제시하였으며, 이를 적용한 시뮬레이션 결과에 의하면 항상 원하는 해(true solution)에 수렴할 수 있었다.발생량의 감소를 기대 할 수 있는 친환경기술로 유지관리비를 최소화할 수 있는 장점이 있었다. 않은 사람들 중 미래의 검진실행의지에 건강소식지가 영향을 미친 경우는 48.7%였다. 보건교육을 받은 후 유방암 자가검진 실천율은 사업군에서 53.9%로 받기 전의 27.3%보다 증가하였으나 대조군의 경우는 별 차이가 없었다. 연령별로는 60대가 가장 높았고 사업군에서 검진율의 증가분은 30대가 가장 컸다. 교육수준별로는 사업군은 고졸이, 대조군은 전문대졸이 가장 높았고 사업군에서 검진율의 증가분은 고졸에서 가장 컸다. 보건교육 후 유방암과 관련된 건강지식의 정도는 사업군이 3.7점으로 대조군보다 유의하게 높았으며, 유방암 자가검진법을 실천하는 사람들의 동기는 ‘일반 대중매체의 영향’이 가장 많았으며 건강소식지가 동기인 경우도 20.4%였다. 사업군에서 건강소식지가 유방암 자가검진법 실천에 영향을 미친 경우가 79.6%였으며 유방암 자가검진법에 관한 보건교육을 받고 실천하지 않은 사람들 중 미래의 실천의지에 건강소식지가 영향을 미친 경우는 43.6%였다. 이상의 소견에서 지역주민을 대상으로 인쇄매체를 통한 보건교육은 인쇄물만으로도 쉽게 실천 할 수 있는 유방암 자가검진법이 가장 효과적이었으며, 자궁암검진에 관해서도 검진을 받을 수 있도록 지역사회의 보건의료의 하부구조를 정비하여 제도적 장치를 마련하고 정보를 제공한다면 자궁암검진 실천율도 증가할 것이다.고 12.9% 의 발달율을 보여 유의적인 차이를 보이지 않았다. 이상의 결과로 보아 핵이식 수정란을 효율적으로 생산하기 위하여 수핵난자의 세포질에 ionomycin 과 DMAP 의 혼합처리로 탈핵난자의 활성화를 유도하는 것이 효율을 증진시킬 수 있었다고 본다. 또한 공핵수정란을 수정 후 90시간과 114시간 개별 배양하여 할구를 공핵체로 핵이식에 이용하였을 때도 그룹배양에 비하여 효율이 떨어지지 않음을 알 수 있었으며, 수정란의 할구

• Clinical and Experimental Reproductive Medicine
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• 제36권1호
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• pp.45-53
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• 2009

목 적: 본 연구는 정상 정액을 배양액으로 세척한 후 $4^{\circ}C$, $22^{\circ}C$, $37^{\circ}C$에서 5일 동안 보존하면서 정자의 운동성, 생존성을 관찰하여 정자의 운동성과 수명 유지를 위한 적정 배양 환경을 분석하고자 하였다. 연구방법: 정액검사 시 정상으로 판정된 남성의 정자를 HTALP 배양액으로 세척하여 정자의 최종 농도 $1{\times}10^6/ml$로 각 5 ml을 배양온도 $4^{\circ}C$, $22^{\circ}C$, $37^{\circ}C$에서 5일 동안 배양하였다. 1일, 3일 5일째에 CASA에 의해 운동성을 측정하였고, HOST로 정자막의 온전성을 분석하였으며, CTC pattern으로 수정능획득 상태 분석하여 최적의 배양 환경을 분석하였다. 결 과: 정자의 운동성, 생존성 및 수정능획득이 야기되지 않은 정자는 배양일에 따라 유의하게 감소하였다 (p<0.05). 또한 정자 배양 후 1일에는 정자의 운동성, 생존성 및 정자막의 온전성과 CTC pattern은 온도에 따라 차이가 없었으나, 배양 후 3일과 5일에서는 $22^{\circ}C$에서 배양된 정자가 다른 배양온도에 비해 가장 잘 보존되었다 (p<0.05). 결 론: HTALP로 세척된 정자를 $22^{\circ}C$에서 보존 시 5일까지 정자의 운동성과 수명을 보조생식술에 적합한 수준으로 유지시킬 수 있는 최적 배양 환경으로 제시할 수 있다.