Electoromyographic Study of Hip Circle forward in Horizontal Bar

Objectives of this paper were to elucidate key factors of hip circle forward on horizontal bar from electromyographic point of view. Subjects employed in the experiments were 7 healthy male adults, ranging from skilled subjects to non-skilled. Electromyograms (EMGs) were recorded by conventional method using surface electrodes from the flexor carpi radialis, the extensor carpi radialis brevis, the biceps brachii long head, the triceps brachii lateral head, the deltoid anterior, the deltoid posterior, the pectoralis major abdominal portion, the latissimus dorsi, the rectus abdominalis, and the sacro-spinalis. Side-view motion pictures, angular change of wrist joint and strain values of horizontal bar were simultaneously recorded with the EMGs. In the skilled subjects, the hip circle forward was performed successfully to get the rotatory power using the angular changes of the hip joint effectively. On the other hand, in the unskilled subjects, the hip circle forward was carried out using the arm pull movement as well as the angular changes of the hip joint. The regrasping with the hands, which is indicated in the teaching manuals as one of the most im portant key factors of the hip circle forward, is not necessary when the rotation of the hip circle for ward was done smoothly. Non-skilled subjects were trained based on the results of the motion analyses of hip circle forward which have been obtained by author and others. As a result, they were able to perform the hip circle forward. However, in one of the two subjects, the unnecessary contraction of the shoulder girdle and trunk muscles were still remained; in the other, the discharge patterns of the muscles tested approached those of the unskilled.