ELECTROMECHANICAL DELAY OF UPPER AND LOWER LIMBS

Abstract

866 The purpose of this study was to measure electromechanical delay (EMD) under isometric, concentric and eccentric conditions in extension and flexion movements of elbow and knee joints, and planter flexion and dorsal flexion of ankle joint, and to examine whether peculiarity was seen in the EMD of each joint. The subjects were six males and ten females undergraduate untrained students. The measurement of EMD was performed using a dynamometer (KinCom) with the angular velocity of 0°/sec (isometric muscle action) and 60°/sec (concentric and eccentric muscle actions) respectively, and all tests was performed with the force levels of 100% maximum voluntary contraction. As a result, the EMD of elbow and knee joints showed a significant shorter value (p<0.05∼p<0.01) in extension than in flexion. Also, ankle joint showed a significant shorter value of EMD in planter flexion than in dorsal flexion. The EMD between the each joint (elbow, knee and ankle) was the shortest value in the ankle joint, the second shortest value was elbow joint, and the third shortest value was knee joint. The EMD between the each muscle action (isometric, concentric and eccentric) showed a significant shorter value (p<0.05∼p<0.01) in eccentric muscle action than in isometric and concentric muscle actions both each joint. Furthermore, the shortest value was 53.3 ± 9.5 msec (eccentric muscle action) in planter flexion of ankle joint. These results cleared that a difference was seen in EMD of each joint. It was considered that, this difference was probably caused by internal factor of muscle (in words, in such cases as the muscle composition) and the character of the agonist and antagonist, and so on.