• 대한의용생체공학회:의공학회지
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• 제34권3호
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• pp.156-162
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• 2013

Moments of inertia of limb segments are essential to calculate parameters related to the segmental rotation. To analyze the human motion accurately and specifically, moments of inertia obtained from the individual are required. In this study, a simple method to determine a subject-specific moment of segmental inertia using a dynamometer is introduced. In order to evaluate the method, one male participated to test for his forearm plus hand on a commercial dynamometer. Three passive speeds, i.e. 240, 270, and $300^{\circ}/s$, were chosen to confirm whether the moment of inertia values at each speed approach to a fixed value. The same procedure was repeated on the day after to evaluate whether the method is reproducible. As the results, there were no significant differences among the speeds and between the days. The value of the moment of the forearm inertia was 0.216 $kg{\cdot}m^2$ that is apparently higher compared to values by previous models. Nonetheless, it seems to be acceptable based on our body mass index analysis using reported subject height and mass in each previous study. According to our results, the developed method could be useful to determine the segmental moment of inertia of an individual, showing no significant differences among the speeds and between the days. Thus, we believe that our results are reliable according to two appropriate evaluation procedures. This finding would be helpful to calculate segmental rotation related parameters of an individual.

• 한국운동역학회지
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• 제20권2호
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• pp.149-154
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• 2010

Intentional draw and fade shots could be good weapons for lowering golf score. But how to make such shots? To investigate deterministic variables generating different projectile paths of shots in square stance was the purpose of this study. Ten right-handed male collegiate athletes, showing 1.3 of averaged handicap, participated in this study. They were asked to intentionally perform three different shots such as the straight shot(control condition), draw shot, and fade shot. Swing path, pelvis rotation angle, thorax rotation angle and left forearm supination angle were determined for dependent variables on impact event at each trial. For statistical analysis one-way repeated measures ANOVA were used. The results showed that swing path was one of main factor making differences among three kind of shots. Straight shot vs. Draw shot, Straight shot vs. Fade shot and Draw shot vs. Fade shot showed differences on swing path. And left forearm supination angle revealed significant difference between draw shot and fade shot, showing a significant larger angle of draw shot than fade shot. No other significant difference was detected for the other variables. We found that the shot characteristics were influenced primarily by swing path and left forearm supination angle.

• 대한전기학회논문지
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• 제41권9호
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• pp.1051-1059
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• 1992

In this paper, two general methods using time-series analysis in the functional separation of the myoelectric signal of human arm movements are developed. Autocorrelation, covariance method and sequential least squares algorithm were used to determine the model parameters and the order of signal model to describe six arm movement patterns` the forearm flexion and extension, the wrist pronation and supination, rotation-in and rotation-out. The confidence interval to classify the functions of arm movement was defined by the mean and standard deviation of total squared error. With the error signals of autoregressive(AR) model, the result showed that the highest success rate was obtained in the case of 4th order, and success rate was decreased with increase of order. Autocorrelation was the method of choice for better success rate. This technique might be applied to biomedical and rehabilitation engineering.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1944-1947
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• 2005

In this paper, the control of a prosthetic arm using the flex sensor signal is described. The flex sensors are attached to the biceps and triceps brchii muscle. The signals are passed a differential amplifier and noise filter. And then the signals are converted to digital data by PCI 6036E ADC. From the data, position and velocity of arm joint are obtained. Also motion of the forearm - flexion and extension, the pronation and supination are abstracted from the data by proposed algorithm. A two D.O.F arm with RC servo-motor is designed for experiment. The arm length is 200 mm, weight is 4.5 N. The rotation angle of elbow joint is $120^{\circ}$. Also the rotation angle of the wrist is $180^{\circ}$. Through the experiment, we verified the possibility of the prosthetic arm control using the flex sensor signal. We will try to improve the control accuracy of the prosthetic arm continuously.

• 전자공학회논문지B
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• 제30B권4호
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• pp.76-84
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• 1993

In this thesis, general method using autoregressive model in the functional separation of the myoelectric signal of human arm movements are suggested. Covariance method and sequential least squares algorithm were used to determine the model parameters and the order of signal model to describe six arm movement patterns` the forearm flexion and extension, the wrist pronation and supination, rotation-in and rotation out. The confidence interval to classify the functions of arm movement was defined by the mean and standard deviation of total squares error. With the error signals of autoregressive(AR) model, the result showed that the highest success, rate was abtained in the case of 4th order, and success rate was decreased with increase of order. This technique might be applied to biomedical-and rehabilitation-engi-neering.

• 한국운동역학회지
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• 제21권1호
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• pp.39-46
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• 2011

The purpose of this study was to examine differences between players who bend the left elbow and those who stretch it during the forward swing from BST to BC in a 2-handed backhand stroke among outstanding high school tennis players, and to assess the detailed 3D rotational kinematic characteristics of the shoulder and the hip. Statistically significant differences were observed between groups in the longitudinal axis rotation angle of the shoulder and the angle between the shoulder and the arm at BST, and in the side to side movement of the shoulder, the up and down movement of the hip, the side tilt angular velocity of the shoulder, the side tilt angular velocity of the hip, and the front tilt angular velocity of the hip at BC. The difference in the longitudinal axis rotation angle of the shoulder between the 2 groups suggests a difference in the flexibility of the joint in the shoulder arm racquet system. The longitudinal axis rotation angular velocity of the shoulder reached its peak at 75 % of the duration of the analyzed segment and then decreased little by little until BC. This time is considered the stage for increasing the angular velocity of the upper arm, the forearm, the hand and then the racquet, which are more distal segments than the shoulder.

• 한국운동역학회지
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• 제16권3호
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• pp.33-41
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• 2006

This study was to analysis three dimension angle of the upper extremity segment and trunk to putting the protector in women bowlers. For this study, the subjects selected 4 players of national and university team. All subjects putted in the same wrist support to satisfy the experiment conditions. To get three dimensions position coordination of swing motion used for 6 ProReflex MCU 240 camera produced by Qualisys. After position coordination calculation, Three dimension angle of the trunk and the upper extremity segment calculated for Matlab 6.5. the result is following; In the trunk motion, there were little differences among the subjects in a flexion and extension change. There were a lot of differences in motion change of the abduction-adduction and internal-external rotation, but the motion types translated to the adduction-abduction-adduction and from the internal rotation toward the external rotation. In the upper arm segment the Flexion and extension showed a consistent motion in the down swing and up swing phase. And the motion change of abduction-adduction and pronation-supination showed a abduction-adduction-abduction and pronation-supination change during swing phase. In the forearm segment changes, it showed a lot of differences among the subjects and a similar change with the upper arm segment. Especially, the hand segment showed a supination motion from the backswing apex to release phase, but for increasing a rotation velocity of ball, the hand segment translated toward pronation in follow throw phase.

• 대한방사선기술학회지:방사선기술과학
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• 제33권1호
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• pp.19-24
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• 2010

본 연구는 원위요골의 회전에 따른 골밀도의 변화를 알아보고 원위요골 골밀도와 요추 골밀도를 비교 분석하였다. 골밀도 측정시 정확한 측정 자세를 알아보고자 자체 제작한 보조기구를 이용하여 수술, 기형이나 외상력이 없는 20, 30대 남성 11명을 대상으로 전완부를 DR(digital diagnostic IR-1100-150 ; Philips)로 촬영하였고 남성 21명을 DXA(QDR 4500W ; HOLOGIC, USA)로 골밀도 측정을 시행하였다. 실험은 두 가지로 수행하였다. 첫째, 보조기구를 이용하여 11명을 대상으로 전완부를 DR로 중립위(0도)를 기준으로 내회전 및 외회전 각각 3, 6, 9도에서 촬영하였고 둘째, 요추 및 전완부(Forearm)의 골밀도를 21명을 대상으로 DXA 장비를 이용해 중립위(0도)를 기준으로 내회전 및 외회전 각각 5, 10도에서 측정하였고 통계프로그램 SPSS 12.0v으로 비교 분석하였다. 그 결과 DR로 촬영한 11명의 원위요골 회전각은 내회전인 경우가 82%(n = 9)로 가장 많았으며, 평균 내회전 각도는 7도였다. 외회전 6도와 중립위(0도)에서도 1명(9%)씩 나타났다. 전체평균 회전각은 내회전 5.1도였다. DXA로 측정한 21명의 원위요골 회전각은 내회전인 경우가 43%(n = 9)로 가장 많았으며, 평균 내회전 각도는 7.2도였다. 외회전은 24%(n = 5)이고 평균 외회전 각은 6도이며 중립위(0도)은 33%(n = 7)로 나타났다. 전체평균 회전각은 내회전 4.1도였다. 요추와 원위요골의 상관 계수는 r = 0.30, p = 0.18로 통계적 유의성은 없었다. 요추의 골밀도가 원위요골의 골밀도를 대변하지 못하기 때문에 원위요골 골밀도의 평가는 원위요골에서 측정해야 한다. 전완부 골밀도 측정시 중립위는 원위요골이 외회전이 대부분이기 때문에 최저 골밀도의 회전각에서 일정하게 골밀도를 측정하기 위해서는 중립위 보다 내회전이 필요하며 내회전 각은 약 5도가 추천된다.

• 한국운동역학회지
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• 제13권1호
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• pp.185-204
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• 2003

The purpose of this study was to obtain the data for stable and accurate techniques of the free throw in basketball. The subjects of this study were seven male basketball player consisted of college students athletes. Free throw motions were taken by video camera. The three-dimensional coordinates was processed by DLT. The variables were the velocity, the angular velocity of the upper extremity segments, degree, and angular momentum. The result of analysis is summarized as follows. 1. The velocity and angular velocity of the upper extremity segment was showed an gradual increase and a smooth velocity transfer, transferring from proximal segment to distal segment at free throw motion in basketball. 2. The local term and remote term angular velocity momentum of the proximal segment showed larger than that of the distal segment in X, Y, Z axis component all. 3. The remote term angular momentum was showed larger than that of the local term angular momentum in X, Y, Z axis component all. 4. The angular motion of the upper trunk and upper arm, upper arm and forearm was showed in opposite direction and symmetrical angular momentum in local term angular momentum of the Y and Z axis component. 5. All the segments of upper extremity segment was showed left rotation in remote term angular momentum of the Y axis component and right rotation in remote term angular momentum of the Z axis component.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.250-252
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• 2007

In this paper presents a control algorism for myoelectric hand prosthesis(MHP) with 2 degree of freedom(DOF), which consists of a mechanical hand, a surface myoelectric sensor(SMES) for measuring myoelectric signal, a control system and a charging battery. The actuation for the 2-DOF hand functions such as grasping and wrist rotation was performed by two DC-motors, and controlled by myoelectric signal measured from the residual forearm muscle. The two controllers were made of a RISC-type microprocessor, and its software was executed on a real-time kernel. The experimental results were showed that the proposed a control algorism is feasible for the MHP.