The comparison of joint kinematic error using the absolute and relative coordinate systems for human gait

임용훈,최안렬,민경기,금동혁,최창현,문정환,이상식 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.1

Minimizing artifacts from skin movement is vital for acquiring more accurate kinematic data in human movement analysis. There are several stages that cause skin movement artifacts and these stages depend on the selection of the reference system, the error reduction method and the coordinate system in clinical gait analysis. Due to residual errors, which are applied to the Euler and Bryant angle methods in each stage, significant cumulative errors are generated in the motion analysis procedure. Thus, there is currently a great deal of research focusing on reducing kinematic errors through error reduction methods and kinematic error estimations in relation to the reference system. However, there have been no studies that have systematically examined the effects of the selected coordinate system on the estimation of kinematic errors, because most of these previous studies have been mainly concerned with the analysis of human movement using only the human models that are provided in the commercial 3D motion capture systems. Therefore, we have estimated the differences between the results of human movement analyses using an absolute coordinate system and a relative coordinate system during a gait, in order to establish which system provides a more accurate kinematic analysis at the ankle joint. Six normal adult subjects with no neurological or orthopedic conditions, lower extremity injuries, or recent history of lower extremity surgery were used in this study. The analysis was conducted at a walking speed of 1.35m/s. For the clinical estimation, we used a cardinal plane based on the segmental reference system and the differences were plotted on the planes. From this analysis, when a relative coordinate system was in the gait analysis, the average kinematic error occurring during the gait was determined to be 13.58mm, which was significantly higher than the error generated with an absolute coordinate system. Therefore, although the relative coordinate system can also be used to calculate the ankle joint center during the clinical gait analysis, the absolute coordinate system should be employed in order to obtain more accurate joint kinematic data. In addition, the results from this study can be used as a basis to select an appropriate coordinate system with regards to the diagnostic accuracy level required for various kinds of gait disorders.

발레 Developpe a La Seconde 동작 시 하지의 운동학적 변인 비교 분석

정은지 ( Eun Ji Jung ),이정연 ( Jeong Yeon Lee ) 대한무용학회 2009 대한무용학회논문집 Vol.61 No.-

This In this study, duration of the movement, shift in center of the body, difference in the height of the knees, angle of the ankle, knee, hip-joint, angle of the trunk inclination of two sample groups one of 5 skilled with training for more than 7 years and another of 5 unskilled with training less than 2 years executing "developpe a la seconde" were analyzed using 3-dimensional image analysis, followed by comparative analysis. 1) Timing Variation No significant difference observed. Inter-phase comparative analysis shows the greatest timing variation in PH4. 2) Positioning Variation Inter-group comparative analysis of shift in center of the body shows significant differences in E3, E4. Inter-event comparative analysis shows significantly high value in E3, E4 for the skilled group, and in E2, E3, E4 for the unskilled group. 3) Angular Variation Inter-group comparative analysis of the angle of the ankle joint shows significant differences in E2. Inter-event comparative analysis shows significantly high value in E2 for the skilled group, and in E2, E3, E4 for the unskilled group. Inter-group comparative analysis of the angle of the knee joint shows no significant difference. Inter-event comparative analysis shows significantly high value in E4 for the skilled group, and in E4, E5 for the unskilled group. Inter-group comparative analysis of the angle of the hip joint shows no significant difference. Inter-event comparative analysis shows significantly high value in E3, E4 for both the skilled and unskilled group. Inter-group comparative analysis of the angle of the trunk inclination shows significant differences in E3, E4. Inter-event comparative analysis shows significantly high value in E3, E4 for the skilled group, and in E4 for the unskilled group In conclusion, for the correct execution of developpe a la seconde, pull up is a necessity in order for maintaining balance relevant to the duration of the movement. Also, knees must be maintained at the maximum possible height through the motion leading to developpe from passe through attitude. Larger angle between the supporting leg and the hip joint results in superior aesthetics and functionality, and although the wider range of motion of lower extremity require inclination of the upper body for stability, for the aesthetic purpose upright positioning of the upper body should be practiced.

발레동작의 정성분석모형과 운동역학적 분석

권안숙(An Sok Gwon) 한국무용과학회 2006 한국무용과학회지 Vol.12 No.-

본 연구는 아라베스크회전동작을 5단계 즉 준비 내 딛기, 서기, 회전, 마무리단계로 구분, 정성분석 모형을 개발하여 주요요인을 도출하고 나아가 영상분식과 지면반력분석을 수행하였다. 이러한 동작을 어느 수준까지 일관성 있게 수행할 수 있는 숙련자를 2명을 대상으로 정성분석 모형에서의 각 단계별 주요요인을 바탕으로 지면반력 분석을 통하여 발현되는 힘의 영상을 파악하고, 영상분석을 통하여 시간, 각도, 회전각도, 동작의 궤적 등 동작에 대한 연구를 다각적으로 수행함으로써 무용수의 체계적인 훈련과 연습을 위한 동작 단계별 구조 및 기능에 관한 정확한 정보를 제공하기 위한 분석을 실시하였다. 분석 결과 다음과 같은 결론을 얻었다. 1. 준비 단계에서는 두발 가운데 중심을 두고 발바닥에 고르게 체중을 분배하여 지면을 미는 힘 Fz 값을 크게 하며, 두 다리의 신전 각을 같이하고 몸통과 머리를 곧게 펴며 신체정렬이 잘 이루어지는 것이 주요요인으로 나타났다. 2. 내 딛기 단계에서는 정확한 동작을 수행하기 위해서는 왼발 뒤꿈치가 들리지 않은 상태에서 상체를 곧게 펴고 발목(100∼110도), 무릎각도(150~155도)를 굴곡 시킨 후 내딛는 발(오른 발)을 신전시키는 것이 중요하다. 이때 왼발로는 균형을 최대한 유지하기 위한 노력을 기울이는 것이 중요하다. 3. 서기 단계에서는 원활하게 서기동작을 수행하기 위해 왼발로는 지면을 수직으로 누르는 힘 발현이 중요하며, Fx 방향으로 반력(음의 Fx)을 발현해 서기동작과 더불어 회전을 원활하게 유지시키기 위한 회전력을 만드는 것이 중요하다. 이때 상체는 곧게 펴 있어야 하며 오른 발은 완전 신전상태를 유지해야 한다. 4. 회전 단계에서는 오른발의 수직축과 뒤로 뻗어 든 다리의 신전상태유지 그리고 두 팔이 외전하는 방향을 따라 회전하는 궤적이 매끄러워야 하며 이때 회전을 일으키는 왼발이 지면에서 이탈될 때 타이밍과 지지하는 오른 발의 힘(Fx, Fy값)을 유지하는 것이 주요요인으로 나타났다. 5. 마무리 단계에서는 회전 후 균형을 유지하기 위해 지면을 미는 힘 Fz값은 커지고 Fx, Fy값은 0인 상태에서 중심축을 이루며, 지지한 오른 다리 신전을 완전히 시키고(발목 각, 무릎 각, 고관절) 뒤로 뻗어 든 다리의 수평상태에서 풀업자세를 유지하는 것이 주요요인으로 나타났다. 비록 숙련자라 할지라도 부상을 줄이고 기술향상 위해서는 신체동작의 메카니즘을 다각적 관점에서 이해해야 하고 자신의 특성을 포함한 체계적인 동작 분석정보를 제공받아야 한다. 그러기 위해서는 우선적으로 전문가의 체계적인 관찰을 통해 객관적이고 정밀한 평가모형을 개발하고 여기서 제시된 주요 요인들을 근거로 영상분석(시간, 각도, 회전각도, 궤적 등)과 지면반력 분석을 연계한다면, 보다 전문적이고 체계작인 동작에 대한 정보를 무용수에게 제공해 줄 수 있다고 사료된다. 난이도가 높고 복잡한 동작일수록 정성분석평가 모형을 개발하여 제시하고 운동학적, 운동역학적 분석과 연계하여 동작에 대한 이해도를 높인다면 상호 시너지 효과를 가져와 동작 분석의 차원을 한 단계 높일 수 있다고 제언한다. This study is performed to develop the qualitative analysis model, in which the movement is divided into the 5 phases, the preliminaries, step-forward movement standing, rotation, finish phases, to identify the critical factors in each phases. On the basis of the model, the cinematographic analysis and the ground reactive force analysis is performed. Because this movement can be performed only with being harmonized by the proper representation and the peculiar characteristic(ability), this study is performed the analyses to offer the accurate information on the structure and the function by movement stage, aiming at a dancer's systematic training and practice, by grasping the aspects of the force, which are revealed through the ground reaction force, targeting 2 experts who can consistently perform up to a certain level, and by diversifiedly performing a research on movements such as time, angle, rotational angle, and the trace in movement through cinematographic analysis. The result of the analyses are as follows: 1. In the preliminary stage, it is a critical factor that makes the body alignment well attained, with putting the center in the middle of two feet and straightly stretches the body and the head by allowing the stretching angle in two legs to be equal. 2. It is important to stretch the stepping foot (right foot) after allowing ankle and knee angle to be curved, with straightly stretching the upper body, in a state that the heel of left foot was not lifted. 3. In the standing stage, it is important in the manifestation of force that vertically pushes the ground from the left foot aiming to smoothly perform the standing movement and is vital to make the rotational force in a bid to smoothly maintain the rotation together with the standing movement by manifesting the reaction force (negative Fx) in the direction of Fx. 4. In the rotational stage, it is a critical factor that maintains the timing and the right force (Fx, Fy value) when the left leg, which causes the rotation at this time, separates from the ground. 5. In the finishing stage, aiming to maintain the balance after the rotation, it is a critical factor to attain the central axis and to maintain the pull-up posture in a horizontal state of the leg that stretched up backward. Even if the dancer is an expert, to decrease injuries and to elevate technical skills, she has to understand the mechanism of the body movement from many angles and has to be furnished with a systematical analytical information on her movement, including her characteristics. For this, preferentially it is necessary to develop an objective and elaborate analysis model by the systematical observations of an expert which presents critical factors issued on this report and if we can connect the cinematographic and the ground reaction force analysis on the basis of them, it is considered that we can present a dancer with the more professional and systematic information on the movements. The higher the degree of difficulty and the more sophisticated the movements, the qualitative analysis model (or those should be developed and presented and be connected to kinematic and kinematical analysis. if it produces synergy effects by improving the understanding, we could set up the level of the movement analysis.

삼량진-밀양 지역에 위치한 도로 절취사면에 대한 사면안정 연구

엄정기(Jeong-Gi Um),강태승(Taeseung Kang),황진연(Jin Yeon Hwang) 대한자원환경지질학회 2005 자원환경지질 Vol.38 No.3

본 연구는 도로 절취사면에 대한 사면안정 연구로서 삼량진과 밀양을 연결하는 1022호 지방도 중 천태산 부근에 위치한 약 4 km의 연속적인 절취사면에서 수행되었다. 연구지역은 유문암질 회류응회암, 강하응회암, 유문암 및 안산암 등의 백악기 화산암류로 구성되어 있으며, 거의 전 구간에 걸쳐 70 o 이상의 사면각으로 형성된 절취암반은 높은 빈도의 불연속면을 포함하고 있다. 암반사면의 불안정 요인으로 작용하는 불연속면의 기하학적 분포특성을 파악하기 위하여 8개 지점에서 선형조사선 조사를 실시하였으며, 조사 자료에 대하여 운동학적 해석 및 블록이론해석을 적용하여 대상 도로 절취사면의 안정성을 검토하였다. 각각의 선형조사선에서 조사된 개별 불연속면에 대한 중력 재하의 평면 파괴, 쐐기 파괴, 및 전도 파괴 등에 대한 최대안전사면각을 산정한 결과, 평면파괴에 대한 최대안전사면각은 대부분의 개별 불연속면 에서 65 o 이상으로 나타났으며, 쐐기파괴에 대한 최대안전사면각은 45 o 이상으로 산정되었다. 또한, 전도파괴에 대해서는 대부분의 개별 불연속면에서 80 o 이상으로 산정되었다. 블록이론을 적용한 결과 SL4, SL5, SL6 및 SL8 지점에 존재하는 잠재적 키블록(Type II)을 확인하였다. 블록이론에 의해 구분된 잠재적 키블록에 대하여 한계평형해석을 수행한 결과 중력재하에서는 1보다 큰 안전율이 확보되었으나 집중호우 시 나타날 수 있는 간극수압과 같은 외적 사면 불안정 요인에 따라 안전율이 크게 저하될 수 있음을 도출하였다. 또한, 한계평형해석 시 적용되는 Mohr-Coulomb 및 Barton 등의 전단강도 기준식에 따른 안전율의 변화를 제시하였다. This study addresses the preliminary results of rock slope stability analyses including hazard assessments for slope failure conducted on the selected sections of rural road cut slope which are about 4 km long. The study area is located in the Mt. Chuntae northeast of Busan and mainly composed of Cretaceous rhyolitic ash-flow tuff, fallout tuff, rhyolite and andesite. The volcanic rock mass in the area has a number of discontinuities that produce a potentially unstable slope, as the present cut slope is more than 70 degrees in most of the slope sections. Discontinuity geometry data were collected at selected 8 scanline sections and analyzed to estimate important discontinuity geometry parameters to perform rock slope kinematic and block theory analyses. Kinematic analysis for plane sliding has resulted in maximum safe slope angles greater than 65 o for most of the discontinuities. For most of the wedges, maximum safe cut slope angles greater than 45 o were obtained. Maximum safe slope angles greater than 80 o were obtained for most of the discontinuities in the toppling case. The block theory analysis resulted in the identification of potential key blocks (type II) in the SL4, SL5, SL6 and SL8 sections. The chance of sliding taking place through a type II block under a combined gravitational and external loading is quite high in the investigated area. The results support in-field observations of a potentially unstable slope that could become hazardous under external forces. The results obtained through limit equilibrium slope stability analyses show how a stable slope can become an unstable slope as the water pressure acting on joints increases and how a stable slope under Barton s shear strength criterion can fail as the worst case scenario of using Mohr-Coulomb c

체간의 기능적인 움직임분석을 통한 근육 및 경근(經筋)에 대한 고찰

송윤경,임형호,박성호,Song, Yun-Kyung,Lim, Hyung-Ho,Park, Sung-Ho 척추신경추나의학회 2004 대한추나의학회지 Vol.5 No.1

Until now, there have been no study about kinematic analysis of trunk with meridian muscular system. The purpose of this article is to contribute to the knowledge of meridian muscles of trunk that are related with breathing and basic movements. We research into respiration mechanics analysis and basic trunk movement analysis. And we suggest that the studies of the therapy that apply meridian muscles in trunk and respiration abnormality are more necessary.

체간의 기능적인 움직임분석을 통한 근육 및 經筋에 대한 고찰

박성호(Sung-Ho Park),송윤경(Yun-Kyung Song),임형호(Hyung-Ho Lim) 척추신경추나의학회 2004 대한추나의학회지 Vol.5 No.1

Until now, there have been no study about kinematic analysis of trunk with meridian muscular system. The purpose of this article is to contribute to the knowledge of meridian muscles of trunk that are related with breathing and basic movements. We research into respiration mechanics analysis and basic trunk movement analysis. And we suggest that the studies of the therapy that apply meridian muscles in trunk and respiration abnormality are more necessary.

Kinematic Analysis for Improving the Starting Technique in 500-m Speed Skating

( Joo-ho Song ),( Tae-beom Seo ),( Jin-sun Kim ) 한국운동역학회 2018 한국운동역학회지 Vol.28 No.3

Objective: In this study, we analyzed kinematic changes in the start phase of speed skating before and after physical training. Method: We introduced a new strength training program (2017) that was improved in terms of exercise type and intensity [%, one repetition maximum (1RM)] compared with the previous strength training program (2016). The new program was applied to elite speed skating athletes (four males and four females). To determine the improvement in starting technique, we recorded race images during the start phase of the 500-m race held in 2016 and 2017. The race images were collected using five high-speed cameras and kinematic characteristics of the start phase were analyzed by three-dimensional image analysis. Results: The 1RMs were improved by 11% on an average after the strength training. In 2017, records of four out of the eight athletes were shortened in terms of the initial lap time (100 m), and 500-m records were shortened in six athletes. The time to nine strokes was shortened in five athletes, and the ratio of correct kinetic chain was increased or maintained at a high level in six athletes. Conclusion: In this study, the new strength training program (2017), applied to elite speed skating athletes, showed a positive effect on starting technique and reduced the record times.

7자유도 로봇(SSRMS)의 역기구학 해석

정용섭 金烏工科大學校 1998 論文集 Vol.19 No.-

A pseudo inverse algorithm has been used for a reverse kinematic analysis of redundant manipulators. In this paper an inverse kinematic analysis of 7 d.o.f. maniulator is presented without using a pesudo inverse matrix which reqiures heavy calculations and causes repeatability problem. A joint angle which includes a geometrical meaning is fixed after the angle is varied to accomplish an objective function. And then the remainning 6 joint angles are calculated by the inverse kinematic analysis. The fixed joint angle can be utilized to avoid a singularity configuration avoidance, an obstacle avoidance and a joint torfque minimization, etc. It shows that eight solution configurations exist for a fixed input joint angle and a given position and orientation of the manipulator.

Three-dimensional kinematic motion analysis of door handling task in people with mild and moderate stroke

( Jung Ah Lee ),( Eun Joo Kim ),( Pil Woo Hwang ),( Han Ram Park ),( Jae Hyuk Bae ),( Jae Nam Kim ) 물리치료재활과학회 2016 Physical therapy rehabilitation science Vol.5 No.3

Objective: This study aimed to quantify one of the useful upper extremity movements to evaluate motor control abilities between the groups of people with mild and moderate arm impairments performing a door handling task. Design: Cross-sectional study. Methods: Twenty-one healthy participants and twenty-one persons with chronic stroke (9 mild stroke and 12 moderate stroke) were recruited for this study. Stroke participants were divided into 2 groups based on Fugle-Meyer Assessment scores of 58-65 (mild arm) and 38-57 (moderate arm). All they performed door handling task including the pronation and supination phases 3 times. We measured some movement factors which were reaction time, movement time, hand of peak velocity, hand of movement units to perform door handling task using the three-dimensional motion analysis. Results: The majority of kinematic variables showed significant differences among study groups (p<0.05). The reaction time, total and phase of movement time, hand of peak velocity ,the number of movement units discriminated between healthy participants and persons with moderate upper limb stroke (p<0.05). In addition, reaction time, total and phase of movement time, the number of movement units discriminated between those with moderate and mild upper limbs of stroke patients (p<0.05). Conclusions: Three-dimensional kinematic motion analysis in this study was a useful tool for assessing the upper extremity function in different subgroups of people with stroke during the door handling task. These kinematic variables may help clinicians understand the arm movements in door handling task and consist of discriminative therapeutic interventions for stroke patients on upper extremity rehabilitation.

Stability analysis of a rock slope in Himalayas

Latha, Gali Madhavi,Garaga, Arunakumari Techno-Press 2010 Geomechanics & engineering Vol.2 No.2

Slope stability analysis of the right abutment of a railway bridge proposed at about 350 m above the ground level, crossing a river and connecting two huge hillocks in the Himalayas, India is presented in this paper. The site is located in a highly active seismic zone. The rock slopes are intensely jointed and the joint spacing and orientation are varying at different locations. Static slope stability of the rock slope is studied using equivalent continuum approach through the most commonly used commercial numerical tools like FLAC and SLOPE/W of GEOSTUDIO. The factor of safety for the slope under static conditions was 1.88 and it was reduced by 46% with the application of earthquake loads in pseudo-static analysis. The results obtained from the slope stability analyses confirmed the global stability of the slope. However, it is very likely that there could be possibility of wedge failures at some of the pier locations. This paper also presents the results from kinematics of right abutment slope for the wedge failure analysis based on stereographic projections. Based on the kinematics, it is recommended to flatten the slope from 50o to 43o to avoid wedge failures at all pier locations.