• Physical Therapy Korea
• /
• v.6 no.4
• /
• pp.36-42
• /
• 1999

본 연구의 목적은 운동제어/학습 또는 운동역학을 연구하는데 중요한 역할을 하는 근전도의 사용과 근전도와 등척성 수축력과의 관계에 나타나는 문제점과 제안점을 조사하는 것이다. 선행연구를 분석한 결과, 등척성 힘의 증가에 따른 근전도의 증가 관계가 선형적 모양으로 나타나지는 않았다. 또한, 선행연구에서 근전도와 등척성 힘 관계를 연구하는데 몇 가지 문제점들이 발견되었다. 이러한 문제점은 선행 연구실험들의 절차상에 차이가 나타났고, 근육의 생리학적인 또는 해부학적인 성질에서 문제점이 논의되었다. 결론적으로, 이러한 문제점들이 해결되지 않는 한 근전도와 등척성 수축력과의 관계는 불분명하게 남아있을 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.5
• /
• pp.2212-2218
• /
• 2012

The purpose of this study was to investigate the influence of different sitting postures on range of motion, strength and proprioceptive sense of neck. Fifteen healthy university students participated in the study. Depending on upright sitting position and slump sitting position, range of motion and joint position sense were measured by using Dualer IQ. Also, the maximum isometric strength and force sense were measured by using linear force. As a result, we found that the maximum angle of neck extension and the maximum isometric strength at flexion were significantly higher in upright posture than in slump posture. Also, the maximum angle of neck flexion and the maximum isometric strength at extension were higher in slump posture than in upright posture. According to the result, proper proprioception can have an beneficial effect on postural revision of neck and body by providing the information that cognize the position of head through and sustain upright posture.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1588-1593
• /
• 2008

This paper describes a real-time isometric pinch force prediction algorithm from surface electromyogram (sEMG) using multilayer perceptron (MLP) for human robot interactive applications. The activities of seven muscles which are observable from surface electrodes and also related to the movements of the thumb and index finger joints were recorded during pinch force experiments. For the successful implementation of the real-time prediction algorithm, an off-line analysis was performed using the recorded activities. Four muscles were selected for the force prediction by using the Fisher linear discriminant analysis among seven muscles, and the four muscle activities provided effective information for mapping sEMG to the pinch force. The MLP structure was designed to make training efficient and to avoid both under- and over-fitting problems. The pinch force prediction algorithm was tested on five volunteers and the results were evaluated using two criteria: normalized root mean squared error (NRMSE) and correlation (CORR). The training time for the subjects was only 2 min 29 sec, but the prediction results were successful with NRMSE = 0.112 ${\pm}$ 0.082 and CORR = 0.932 ${\pm}$ 0.058. These results imply that the proposed algorithm is useful to measure the produced pinch force without force sensors in real-time. The possible applications include controlling bionic finger robot systems to overcome finger paralysis or amputation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.5
• /
• pp.338-346
• /
• 2023

During isometric elbow flexion, forearm length should be an important factor to determine not only joint torque but also maximum endurance time (MET), when the forearm is perpendicular to the direction of the force. The purpose of this paper is to examine the effect of forearm length as an additional factor on empirical models of MET such as an exponential model and a power model during isometric elbow flexion. Thirty volunteers participated in our experiment to measure factor variables such as circumferences and lengths of their upper and lower arms. Their METs were measured according to the percent of maximum voluntary contraction intensity (%MVC). For the multiple linear regression model of ln(MET) using these measurements, significant variables could be observed in %MVC and forearm lengths (P<0.05). The empirical models were assessed by these models using forearm length as the additional factor. Mean absolute deviations (MAD) between the measured METs amd the two empirical models were about 19.4 [s], but MAD using models applied forearm lengths were reduced to about 16.2 [s]. The correlation coefficients and intraclass correlation coefficients were about 0.87, but those applied forearm lengths were increased to about 0.91. These results demonstrated that forearm length was a significant additional factor to the empirical model.