• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.175-180
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• 1993

The nonlinear integro-differential equations of motion of a two-link structurally flexible planar manipulator executing contact tasks are presented. The equations of motion are derived using the extended Hamilton's principle and the Galerkin criterion. Also, Models for the wrist-force sensor and impact that occurs when the manipulator's end point makes contact withthe environment are presented. The dynamic models presented can be used to studythe dynamics of the system and to design controllers.

• 한국인터넷방송통신학회논문지
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• 제21권2호
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• pp.117-124
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• 2021

본 연구는 손목 재활을 위한 신경망을 이용하여 수부 동작 인식해주는 연구이다. 수부의 재활은 손상을 받은 수부의 기능을 최대로 회복시켜 일상생활과 직업, 취미생활을 가능하게 하는 것을 목표로 한다. 하지만 어느 장소를 찾아 치료를 하는 것은 경제적, 시간적으로 매우 비효율적이다. 이런 문제점을 해결하고자 본 연구에서는 환자가 직접 스마트 기기를 이용해 재활 치료를 하고자 한다. 이를 활용하면 비용이나 시간적인 면에서 매우 도움이 될 것이다. 본 연구에서는 총 10명의 사람으로부터 4 종류의 재활 운동에 대한 데이터를 수집하여 손목재활 데이터셋을 만들었다. 수부 제스쳐 인식은 신경망을 이용하여 모델을 구성하였다. 그 결과 93%의 정확도를 얻었으며, 본 시스템의 유용성을 검증하였다.

• 대한안전경영과학회지
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• 제25권2호
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• pp.107-111
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• 2023

This study aims to empirically investigate effects of motion repetition and external load according to joint motion on discomfort through an experiment. Eighteen college students (female: 9; male: 9) participated in an experiment measuring perceived discomfort using the Borg CR10. Joint(wrist, elbow, shoulder and trunk) motion, its repetition and external load were adopted as independent variables. The results showed that all three independent variables were statistically significant on discomfort. Participants' sex also significantly affected discomfort obtained in the experiment. While the interactions of joint motion and repetition, and joint motion and external load were not significant at α = 0.05, that of motion repetition and external load was significant. Based on the experimental results, four regression equations by the joints involved were presented, which could be used as a tool for evaluating postural loads by the joints. It may be postulated that based on the results of this study, scoring systems of RULA and REBA, and those of OWAS and REBA underestimates effects of motion repetition and external load, respectively. It is expected that the results of this study will be used as a basic data for developing an observational method properly reflecting the effects of motion repetition and external load.

• 제어로봇시스템학회논문지
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• 제18권12호
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• pp.1106-1114
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• 2012

To achieve synchronized motion between a wearable robot and a human user, the redundancy must be resolved in the same manner by both systems. According to the seven DOF (Degrees of Freedom) human arm model composed of the shoulder, elbow, and wrist joints, positioning and orientating the wrist in space is a task requiring only six DOFs. Due to this redundancy, a given task can be completed by multiple arm configurations, and thus there exists no unique mathematical solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and their effect on the redundancy resolution of the human arm based on a seven DOF manipulator model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing different cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid for the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each two consecutive points along the task space trajectory. As a first step, the redundancy based on the kinematic criterion will be thoroughly studied based on the motion capture data analysis. Experimental results indicate that by using the proposed redundancy resolution criterion in the kinematic level, error between the predicted and the actual swivel angle acquired from the motor control system is less than five degrees.

• 대한지역사회작업치료학회지
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• 제4권1호
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• pp.23-31
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• 2014

목적 : 본 연구는 정상 성인을 대상으로 일상생활활동 수행하는 동안 기존의 삼차원동작분석 장비와 가속도계에서 발생하는 변수를 동시에 측정하여, 기존의 삼차원동작분석 장비와 가속도계에서 측정된 값의 상관관계를 파악하고 가속도계의 활용 가능성을 제시하고자 하였다. 연구방법 : 성인 20명(남자 10명, 여자 10명)을 대상으로 전화하기, 물 마시기, 세수하기, 숟가락 사용하기를 수행하는 동안 피트미터(Model Fitmeter, Fit.Life, Korea)와 CMS-70P(Zebris Medizintechnik Gmbh, Germany)를 사용하여, 손목 관절과 팔꿉 관절에서 단일벡터크기(Signal Vector Magnitude: SVM) 합과 관절가동범위를 측정하였다. 결과 : 전화하기, 물 마시기, 세수하기, 숟가락 사용하기 수행 시 손목과 팔꿈치에서 발생하는 관절가동범위와 단일벡터크기 합은 과제에 따라 유의한 차이가 있었다(p<.001; p<.001; p<.001; p<.001). 관절가동범위와 단일벡터크기 합은 손목에서는 유의한 상관관계를 보이지 않았으나(p>.05), 팔꿈치에서는 유의한 상관관계를 보였다(p<.01; p<.001; p<.01; p<.05). 손목과 팔꿈치에서 발생하는 단일벡터크기 합의 차이는 전화하기와 세수하기는 손목과 팔꿈치에서 유의한 차이를 보였으나(p<.001; p<.05), 물 마시기와 숟가락 사용하기는 손목과 팔꿈치에서 유의한 차이를 보이지 않았다(p>.05; p>.05). 결론 : 가속도계는 일상생활활동의 역학적 변수를 측정할 때 유용하게 사용할 수 있을 것으로 생각되며, 손목보다는 팔꿈치에서 가속도계가 삼차원동작분석 장비의 기능을 대체할 수 있을 것으로 사료된다.

• 대한물리치료과학회지
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• 제3권2호
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• pp.943-950
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• 1996

Taping is used to restrict undesired, potentially harmful motion and allow desired motion. Taping refers to the application of some type of adhesive backed tape, that adheres to the skin of a particular joint or to a limb. Prevention and rehabilitation is two main indications for the use of taping techniques. The purpose of this study was to compare a tennis injury between taping and non-taping group. The objects of this study were 64 tennis club members-38 non-taping group, 26 taping group. The analysis methods were both frequency and paired T-test. The results are followings: 1. There was effective increase of taping group-elbow, wrist, knee, ankle-that showed significant increase on statistical analysis. (P<.05). 2. There was effective a relation of seasons and injured in taping group-elbow, wrist, ankle-(P<.05) 3. But non-significant statistically about injured seasons. Prophylactic taping has become one of the most common methods employed to prevent sports injuries, despite questions regarding its efficacy. The success of taping does not only depend upon the materials or methods used, but also upon the phychologic sedative effect of the athlete to be taped.

• 한국운동역학회지
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• 제15권2호
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• pp.57-67
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• 2005

The purpose of this study was to analyze the kinetic factors of the golf driver swing using the Inverse Dynamics function. For this purpose, joint force were calculated. In order to test the possibility of Inverse Dynamics function(motion-dependent interaction), a triple segmental system was set for wrist, left shoulder and lumbar and joint force working on the anatomical joint region was estimated. For this study, 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint force and torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint force was generated on wrist, shoulder and lumbar joints in the direction of the target, and that the joint force was stronger in the direction of target immediately before impact. The joint force was generated towards the target to activate the nodes, and then, it was generated in the reverse direction to increase the speed during impact.

• 한국운동역학회지
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• 제21권2호
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• pp.181-187
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• 2011

The purpose of this study was to identify major factors on pirouette in ballet, and especially angle, Center of Mass(CM) & muscle activity aspects. The data were collected by using Motion Analysis System with 12 cameras to analyze kinematic variables with 120 Hz and Electromyography(EMG; 4,000 Hz) & Force Platform(1,000 Hz) to analyze kinetic variables. The subjects of this study were 8 female ballet dancers. The results as follow. First of all, full extension of knee joint and full plantar flexion of ankle joint appeared at the similar point. Secondly, in the rotational phase, total movement of segments in Good motion is smaller than that of Bad motion(in Good motion, head movement 2.70 cm, right shoulder movement 0.72 cm, left shoulder 4.26 cm, left wrist 17.4 mm smaller than Bad motion). Third, CoP distance of Good motion is 11.76 mm, and CoP distance of Bad motion is 11.76 mm, so Good motion is 5.98 mm smaller). Lastly, Pirouette need more retus femur activity than gastrocnemius activity in extention phase and rotation phase of support leg.

• 재활복지공학회논문지
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• 제7권2호
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• pp.69-74
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• 2013

본 연구에서는 손목 움직임의 추정을 위한 근전도 신호 기반 동작 분류 알고리즘을 제안한다. 근전도의 특징점을 추출하기 위하여 절대차분표준편차(DASDV)과 제곱평균제곱근(RMS)을 사용하며, 측정 된 근전도 신호를 이용하여 동작 마다 30개의 특징점(RMS, DASDV)을 추출한다. 근전도 신호를 특정한 패턴으로 나타내어 적용시키기 위하여 평균값을 기준으로 집단을 두 부분으로 나누고, 패턴분류 방법인 k-NN으로 패턴을 학습시킨 후, 집단을 나누지 않은 방법을 사용한 기존의 연구와 비교하여 제안한 알고리즘의 성능을 검증한다. 실험결과 제안한 알고리즘은 92.59%의 인식률을 보였으며, 이전 연구 결과보다 0.84% 포인트의 성능 개선을 보였다.

• 한국산업보건학회지
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• 제8권1호
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• pp.36-49
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• 1998

The purpose of this study is to investigate the relationship between the work postures and upper extremity cumulative trauma disorders(CTDs) in female medical insurance bill reviewers(n=448). This study included diagnosis for CTDs, anthropometry and job analysis (workstations and posture). The characteristics of subject were 33.6 years of average age and 8.7 years of average work duration. The results were as fallows. Ergonomic conditions of workstation were unsuitable compared with anthropometry result. The height of work surface(79.5 cm) and chair(43.0 cm)were high. work space was small, and legs space under the table was limited. Work postures were awkward compared with recommended neutral postures. Neck flexion($21.0-36.0^{\circ}$), elbow elevation, shoulder abduction ($46.0-47.0^{\circ}$). wrist radial and ulnar deviation, forearm supination and pronation, and wrist repeated motion(12.7-21.5 freq./min) were analyzed as hazardous risk factors by job analysis. The prevalence of CTDs was 32.8 % by medical diagnosis. The prevalence rate of CTDs in hazardous work posture group was significantly greater than safe work posture group both neck-shoulder (relative prevalence = 5.2, p<0.001) and wrist-hand (relative prevalence = 2.5, p<0.05).