出版社：Japan Society of Physical Education, Health and Sport Sciences
摘要：Archery is one of the sports which requires both accuracy and strength. Drawing the bow in Japanese archery consists of reversibly directed movements of the bow arm and the string arm depending upon static balance of both legs. Movements of the bow arm and the string arm should be performed at the same time, also the strength of the bow arm should be equal to that of the string arm. Consequently an excellent archer possesses the ability to reproduce exactly the desired position. The purpose of this study was to analyze the muscular activities during the drawing movement from the view point of electromyography. Recording are as follows; 1) EMG of the upper body well recorded by a pair of the surface electrodes. 2) Motion pattern of the elbow joint was recorded by electrogoniometer and respiratory phase was recorded by the thermisterq 3) Force applied to the bow was measured by the semiconductor straingauge. 4) The moment of the arrow release was determined by the microswitch. The subjects for this experiment were three adults. They were one untrained, one middle trained and one trained. The recording are shown in Fig 1,2 and 3. In the first phase of the drawing movement in Japanese archery, both hands with elbow joints extended are raised to shoulder level after "knocking" the arrow. In such a movement, slight action potentials in the arm muscles were seen in EMG of all subjects. The second phase of the movement is a so-called "drawing" in which the left arm (bow arm) was abducted horizontally at shoulder level to the target with elbow joint extending and simultaneously the right arm (string arm) was also abducted with elbow joint flexing. In such a phase, then are some clear differences in the activities of the upper body muscles between the trained and the untrained archers. Namely, the trailed subject drew back the bow with the extensors of the shoulder joint. The left arm was abducted and extended with M.extensor carpi ulnalis, M.triceps brachii, M.deltoideus and M.teres major. The right arm was done with M.triceps brachii, M.deltoideus and M.teres major. On the other hand, the untrained drew the bow mainly with the flexsors of both arm in the first half of drawing motion. Large electrical activities of the right and left M. biceps brachii were seen throughout the drawing movement in addition to the activities of the extensors. The bow was given potential energy, as the abduction of the shoulder joints were carried out. The force curve of the bow, however, showed that the force was applied to the bow smoothly by the trained, while there was seen a fluctuation of the applied force in the case of the untrained. The third phase of the movement is "aiming" which is completely static. There was a great difference in duration of aiming between the trained and the untrained. That is, the untrained was aiming for 2 seconds while the trained aimed for 5 seconds. This difference seemed to depend upon muscular strength or balance of the muscular tension of right and left arms. The last phase of the movement is "releasing". At the moment of release all the muscles of the upper body became active in the untrained, while the trained realized (his muscles) simultaneously. Those activities in the untrained archer might result in the unsteadiness of his release.
其他摘要：Archery is one of the sports which requires both accuracy and strength. Drawing the bow in Japanese archery consists of reversibly directed movements of the bow arm and the string arm depending upon static balance of both legs. Movements of the bow arm and the string arm should be performed at the same time, also the strength of the bow arm should be equal to that of the string arm. Consequently an excellent archer possesses the ability to reproduce exactly the desired position. The purpose of this study was to analyze the muscular activities during the drawing movement from the view point of electromyography. Recording are as follows; 1) EMG of the upper body well recorded by a pair of the surface electrodes. 2) Motion pattern of the elbow joint was recorded by electrogoniometer and respiratory phase was recorded by the thermisterq 3) Force applied to the bow was measured by the semiconductor straingauge. 4) The moment of the arrow release was determined by the microswitch. The subjects for this experiment were three adults. They were one untrained, one middle trained and one trained. The recording are shown in Fig 1,2 and 3. In the first phase of the drawing movement in Japanese archery, both hands with elbow joints extended are raised to shoulder level after "knocking" the arrow. In such a movement, slight action potentials in the arm muscles were seen in EMG of all subjects. The second phase of the movement is a so-called "drawing" in which the left arm (bow arm) was abducted horizontally at shoulder level to the target with elbow joint extending and simultaneously the right arm (string arm) was also abducted with elbow joint flexing. In such a phase, then are some clear differences in the activities of the upper body muscles between the trained and the untrained archers. Namely, the trailed subject drew back the bow with the extensors of the shoulder joint. The left arm was abducted and extended with M.extensor carpi ulnalis, M.triceps brachii, M.deltoideus and M.teres major. The right arm was done with M.triceps brachii, M.deltoideus and M.teres major. On the other hand, the untrained drew the bow mainly with the flexsors of both arm in the first half of drawing motion. Large electrical activities of the right and left M. biceps brachii were seen throughout the drawing movement in addition to the activities of the extensors. The bow was given potential energy, as the abduction of the shoulder joints were carried out. The force curve of the bow, however, showed that the force was applied to the bow smoothly by the trained, while there was seen a fluctuation of the applied force in the case of the untrained. The third phase of the movement is "aiming" which is completely static. There was a great difference in duration of aiming between the trained and the untrained. That is, the untrained was aiming for 2 seconds while the trained aimed for 5 seconds. This difference seemed to depend upon muscular strength or balance of the muscular tension of right and left arms. The last phase of the movement is "releasing". At the moment of release all the muscles of the upper body became active in the untrained, while the trained realized (his muscles) simultaneously. Those activities in the untrained archer might result in the unsteadiness of his release.
