• 한국운동역학회지
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• 제13권3호
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• pp.265-276
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• 2003

The objective of this research is to provide basic data for improving athletic performances, suggesting methods that can be utilized at games and coaching movements in the snatch, by analyzing the level of contribution of muscles to the movements of the snatch lift through three-dimensional imaging and EMG analysis between skilled and unskilled lifters. To this end, three high school students (the skilled group), three middle school student (the unskilled group) were selected; two digital video cameras and electromyography were used. The muscles measured by an EMG include gastrocnemius muscle, biceps femoris muscle, erector spinae, latissimus dorsi muscle, trapezius muscle, and brachioradialis. Based on the Ariel Performance Analysis System (APAS) program, the results of the analysis are summarized as follows. 1. In performing snatch pulls, the skilled lifters were found to simultaneously move the weight centers of the body and the barbell close to vertical, close to the shoulders in the pulling portion; in snatching and grabbing the barbell from a sited position, it was observed that the shorter the time for adjusting to change in the height of the barbell by using rotational inertia, the better it is to perform the movements. 2. The skilled lifters were observed to perform stable and efficient movements in grabbing the bar in a sited position, by moving the barbell and weight center of the body close to vertical and moving the shoulder joint under the bar fast. 3. The results of the EMG analysis of the entire movements from the snatching portion to the portion of grabbing the bar in a sited position show that when the skilled lifters lifted the barbell vertically during the pulling portion, their shoulder joints were extended to put more weight on biceps femoris muscle and brachioradialis; and in snatching and grabbing the bar from a sited position, it was found desirable to increase the myoelectrical activity of erector spinae in order to achieve a balance in the movements of the hip joint between font and rear, as the weight centers of the body and the barbell move higher. On the other hand, the unskilled lifters were found that in response to change in posture, they increase their muscular strength inefficiently in performing the movements throughout the entire lifting process.

• 한국운동역학회지
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• 제34권1호
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• pp.34-44
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• 2024

Objective: This study aimed to investigate how the movements occurring during the follow-through phase after releasing an arrow among elite compound archers, are associated with the arrow impact points on the target. Method: Nine elite archers performed consecutive compound archery shooting under conditions identical to actual competitions using their own bows and equipment. Motion capture system and force platform were utilized to record the changes in joint positions and center of pressure, respectively. Principal component analysis was employed to identify the patterns in which multidimensional joint positions and COP changes were organized with horizontal and vertical coordinates of arrow impact points. Subsequently, correlation analysis quantified the relationship between individual variables and the coordinates of arrow impacts on the target. Results: We found a common organizational pattern in which the two axes of the impact point coordinates were grouped into the first two principal components. The movements of the upper and lower limbs following release exhibited opposite patterns in the anterior-posterior axis, with significant correlations observed between the arrow impact points of the horizontal axis and the left shoulder, right elbow, left hip, and both knees. Additionally, the lateral movements induced by the reaction force upon arrow release showed significant associations with the vertical coordinates of the impact points. Particularly, the correlations between the movements of the left shoulder and elbow, as well as the bilateral hip and right knee, were consistently observed among all participants. Conclusion: These findings implied that the post-release movements could significantly influence the trajectory and impact points of the arrows in compound archery. We suggest that a consistent and controlled movement during the follow-through phase may be more beneficial for optimizing shooting accuracy and precision rather than minimizing movements.

• 복식
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• 제24권
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• pp.235-251
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• 1995

The purpose of this study is to analyze the charateristics of foot according to foot type and analyze the change of foot shape by movements for the sake of making a comfort-able footwears. On the 6 foot type classified by F.I. and F. P. A, this study analyze the surface areas and circumference in the surface area development figure. There are selected eighteen college girls and four movements. The results are as followes : 1. In the 6 foot types classified by F.I. and F. P. A., the circumferences were differed sig-nificantly. 2. In the 6 foot types classified by F.I. and F. P. A., the surface areas were not differed siginificantly. 3. By movements, circumferences and surfaces were not significantly changed according foot type. 4. By movements, the circumference IV, V were changed variously. 5. By movements, surface area of toes, M.P. joint and ankle were changed variously.

• 한국의류학회지
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• 제20권2호
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• pp.257-269
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• 1996

The puropose of this study was to investigate the movement-fitness according to the surface changing of lower limb The experimental items were divided into the lower limb movements (5) and body-shapes (7). This study was done by the expansion and contraction rate consideration of length, girth Also, the lower half of body shape-change on the movements and body-shapes by flat shell was done simultaneously. The summarized findings resulted from experiments and investigation are suggested as follows; First, when commpared the expansion and contraction rate of the length and girth items, the expansion rate of the back crotch length (14~20%), hip girth (10~ 21%) and knee girth (6.2~18.5%) in rabbit leap movement was the most notable among all variables considered in this experimentation. On the others hand, the front croth length (-22~-52%) contracted remarkably. And big-thigh type was the most notable on the body-shape comparision. Second, in comparision of the expansion and contraction rate of the area on the blocks, the expansion of the hip (50~200%) and knee (51~74%) block was the most remarkable. Especially, in the sit on knees movement of the hip-down type expanded 209.4%. Third, in comparision of the lower half of body shape-change, on the movements and body- shapes by the flat shell, under the influence of knee-joint and hip-joint the shape-changs of the hip and knee block was the most notable. But the shape-change of the waist, abdomen, calf, and ankle was feeble.

• Journal of Oral Medicine and Pain
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• 제14권1호
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• pp.57-66
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• 1989

66 patients with temporomandibular disorders were selected for experimental group, and 45 normal subjects who were Dental students were selected for control group. Average age of experimental group was 30.5 years, Male to Female ratio was 2 : 3, and their age distribution were teen-ages to seventh decades. Transcranial radiography (TR) with Denar Accurad 100 was used for each group to get the values of width in joint spaces and to investigate the bony changes of articular surfaces and relative condylar position to articular fossa. In addition to TR, clinical interview and routine charting about amount of mandibular movements and occlusal variations were carried out in experimental group. The obtained results were as follows : 1. The mean values of joint space with in control group were 2.15mm to anterior, 2.98mm to superior and 2.29mm to posterior and the value of relative condylar position to the deepest portion of articular fossa was 0.21mm to anterior. In experimental group, those values were 2.01mm, 2.14mm 2.22mm and 0.12mm to posterior in sequence, respectively. Joint spaces in experimental group, therefore, were inclined to decreased, and relative condylar position was inclined to retrude. Joint space in control group showed symmetric condylar position, but in experimental group showed asymmetry. 2. Non-affected joints with no bony changes in experimental group showed the narrowest joint spaces which were thought to manifest the abnormal stress to non-affected side to dysfunctional state of contralateral affected joints. 3. Amount of mandibular movements in experimental group were within normal values in lateral movements and in protrusive movement but in opening movement with or without passive stretch, those were lower than normal values. Frequency of occlusal variation, for example, protrusive posterior contacts, open bite, median line shift to lateral side were inclined to increase with bony changes and with crepitus.

• 한국의류산업학회지
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• 제22권2호
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• pp.222-232
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• 2020

This study analyzes changes in the knees, hips, and hip joint length according to the different angles of bending knees by 45°, 90°, and 135° respectively for knees, hips, and the hip joint that have high fracture rates when falling down. The research subjects were 10 elderly women in their 60s (or older) that obtain data collected through direct measurement. For analysis, the study drew a diagram of elongation and shrinkage based on changes and change rate from a straight posture (0°) and conducted a statistical analysis on differences of body surface length by zone according to movements. The more the knees were bent, the vertical surface length in front of the knees, the horizontal surface length above the knee line, the horizontal body surface length below the knee lines on the back, and the vertical surface lengths between front side lines and the side lines increased; however, the vertical surface length on the back decreased. For the hip joint, the difference in the vertical surface length was more distinctive when compared to the horizontal. Finally, the horizontal surface length increased below the hips and the vertical surface length increased in most areas except the sidelines and the front. The result of the change in body surface length according to the movements of this study can be utilized in the development of the motion-variable protector.

• 한국운동역학회지
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• 제19권1호
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• pp.77-85
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• 2009

본 연구는 배드민턴 드라이브 동작의 원리와 현상을 이해함은 물론 운동 시 정확한 동작을 유도하여 상해예방 및 기술향상을 기할 수 있도록 기초자료를 제공하고자 하였다. 라헤드의 이동변위는 모든 연구대상자들에게서 비슷한 패턴으로 나타났지만 다소 차이가 나타난 이유로는 신장, 상완과 전완의 길이, 스윙괘적의 개인적인 성향의 등 외부적인 요인에 의한 결과로 사료된다. 국면별 상지관절의 각도를 살펴보면 어깨 관절, 팔꿈치 관절, 손목 관절의 각도는 드라이브 동작을 수행함에 있어 서로 유기적인 관계로 얽혀 있으며 근위에서 원위로 힘의 전달을 한다는 분절 순서이론도 뒷받침하고 있다. 상지관절의 각속도는 연구대상자 모두에서 임팩트 이후 팔로우스루 동작에서도 크게 나타났는데 이는 배드민턴과 같은 라운동에서 팔로우스루의 중요도를 나타내는 것을 의미한다. 이 팔로우스루 동작은 자세의 안정성 유지, 동작의 자세교정, 관절의 상해예방이라는 측면에서 라운동 시 중요요소로 작용하고 있음을 보여주고 있다. 종합해보면 분절의 순서이론에 따른 스윙이 이루어져야 효율적인 동작을 할 수가 있을 것으로 판단된다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.629-634
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• 1995

The purpose of this paper is to develop a method of Collision-Free Path Planning (CFPP) for an articulated robot. First, the configuration of the robot is formed by a set of robot joint angles derived fromm robot inverse kinematics. The joint space that is made of the joint angle set, forms a Configuration space (Cspace). Obstacles in the robot workcell are also transformed and mapped into the Cspace, which makes Cobstacles in the Cspace. (The Cobstacles represented in the Cspace is actually the configurations of the robot causing collision.) Secondly, a connected graph, a kind of roadmap, is constructed from the free configurations in the 3 dimensional Cspace, where the configurations are randomly sampled form the free Cspace. Thirdly, robot paths are optimally in order to minimize of the sum of joint angle movements. A path searching algorithm based on A is employed in determining the paths. Finally, the whole procedures for the CFPP method are illustrated with a 3 axis articulated robot. The main characteristics of the method are; 1) it deals with CFPP for an articulated robot in a 3-dimensional workcell, 2) it guarantees finding a collision free path, if such a path exists, 3) it provides distance optimization in terms of joint angle movements. The whole procedures are implemented by C on an IBM compatible 486 PC. GL (Graphic Library) on an IRIS CAD workstation is utilized to produce fine graphic outputs.

• 대한토목학회논문집
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• 제26권5D호
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• pp.805-812
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• 2006

국내 줄눈콘크리트포장에서 AASHTO 줄눈폭 예측식의 적정성을 판단하기 위하여 줄눈콘크리트 포장의 온도변화에 따른 줄눈폭 움직임을 중부내륙 시험도로에서 모니터링 하였고, AASHTO식과 비교분석을 하였다. 린(Lean)층, 쇄석층, BB3층을 보조기층으로 갖고 있는 포장구역을 조사구간으로 선정하였고, 또한 실런트가 줄눈폭 변화에 영향을 주는 정도를 분석하기 위해 두 구간의 줄눈채움재를 시공하지 않은 구간을 조사 대상으로 포함하여 분석한 결과 실런트가 온도변화에 따른 줄눈폭 움직임에 미치는 영향을 발견할 수 없었다. 조사구간의 줄눈에는 디멕게이지(Demec Gauge)를 설치하여 온도 변화에 따른 줄눈폭 움직임을 측정하였으며, 측정된 결과를 온도에 따른 줄눈폭 움직임을 정량화시켜 분석하기 위해서 ER (Effective Ratio)이라는 개념을 사용하였다. 분석결과 AASHTO 예측식에서는 하부지반 종류에 따라 보정계수(C)가 제안된 것에 반해 시험도로에서 계측된 결과는 하부지반 재료에 따른 줄눈폭 움직임의 차이가 발견되지 않았다.

• 한국멀티미디어학회논문지
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• 제20권8호
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• pp.1248-1257
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• 2017

We propose a frequency estimation algorithm of human movements using Kinect. We collect the 3D coordinates of the joints of a human body and then obtain the frequency-domain description of the movements using the discrete Fourier transform (DFT). By choosing the frequency with the biggest magnitude in the selected frequencies of each of human's joint, we obtain the major beat of the human movements. Experimental results show that the proposed algorithm accurately estimates the frequency of human movements. We expect that the proposed algorithm would be applied to many AR and VR applications as a preprocessing.