Study of Teaching Points to Prevent Tennis Elbow -From the Viewpoints of Muscular Load on the Forearm of the Tennis Players and the Dynamic Features of the Various Tennis Rackets-
【Supercategory：7. DESCENTE SPORTS SCIENCE Subcategory：7.9 Vol.9】
Tennis elbow, epicondylitis, is one of the most well-known sports injuries commonly appeared in tennis players. It was considered that the tennis elbow might be principally caused by overuse of the wrist and elbow. Various new models of tennis rackets with new materials and types are developed by racket manufactures. However, there was little considerations of physiological effects of new model rackets on tennis player.
In the present experiments, electromyographical and kinesiological studies were carried out to elucidate effects of dynamic features of various models of tennis rackets on muscular load on the forearm of tennis players. Tennis rackets used were eight types of four models of different manufacturers. Subjects employed were 11 University Tennis Club members who had participated in the official contests and gained good results. Electromyograms (EMGs) with bipolar surface electrodes were recorded from the extensor carpi radialis brevis and longus, and the flexor carpi radialis and ulnalis muscles. EMGs, strain curve of shaft of the test racket and video motion pictures were simultaneously recorded during forehand and backhand, with single and double hands, strokes with controlled ball by tennis ball machine, and service.
The results obtained in the present experiments were as follows.
(1) The larger moment of inertia of the test racket induced the higher amplitude level of EMGs during the strokes. (2) the smaller face area of the test racket induced the more prolonged vibration of the shaft and the higher amplitude level of EMGs after the ball impact. (3) The stiffness of the shaft of the test racket affects on the low amplitude level of EMGs. However, the softest shaft racket induced high amplitude level activity. (4) The high gut tension of the test racket induced the middle amplitude level of EMGs. (5) The double hand strokes could markedly attenuate the racket vibration and the high amplitude level of EMGs after the ball impact.
Therefore, from the results mentioned above, the following points would be recommended to prevent the tennis elbow for beginners and inferior players.
(1) Racket with larger face area with wider frame, lighter moment of inertia to swing, softer shaft and softer gut tension would be better than that chosen usually. (2) Double hand stroke would be better to learn first than single hand stroke.
DESCENTE SPORTS SCIENCE Vol.9/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
In the present experiments, electromyographical and kinesiological studies were carried out to elucidate effects of dynamic features of various models of tennis rackets on muscular load on the forearm of tennis players. Tennis rackets used were eight types of four models of different manufacturers. Subjects employed were 11 University Tennis Club members who had participated in the official contests and gained good results. Electromyograms (EMGs) with bipolar surface electrodes were recorded from the extensor carpi radialis brevis and longus, and the flexor carpi radialis and ulnalis muscles. EMGs, strain curve of shaft of the test racket and video motion pictures were simultaneously recorded during forehand and backhand, with single and double hands, strokes with controlled ball by tennis ball machine, and service.
The results obtained in the present experiments were as follows.
(1) The larger moment of inertia of the test racket induced the higher amplitude level of EMGs during the strokes. (2) the smaller face area of the test racket induced the more prolonged vibration of the shaft and the higher amplitude level of EMGs after the ball impact. (3) The stiffness of the shaft of the test racket affects on the low amplitude level of EMGs. However, the softest shaft racket induced high amplitude level activity. (4) The high gut tension of the test racket induced the middle amplitude level of EMGs. (5) The double hand strokes could markedly attenuate the racket vibration and the high amplitude level of EMGs after the ball impact.
Therefore, from the results mentioned above, the following points would be recommended to prevent the tennis elbow for beginners and inferior players.
(1) Racket with larger face area with wider frame, lighter moment of inertia to swing, softer shaft and softer gut tension would be better than that chosen usually. (2) Double hand stroke would be better to learn first than single hand stroke.
DESCENTE SPORTS SCIENCE Vol.9/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
| Researcher | Masatada Yoshizawa*1, Yoshio Nemoto*2, Toni Itani*3, Makio Maruyama*4, Minayori Kumamoto*5, Bengt Jonsson*6 |
|---|---|
| University or institution | *1 Department of Eduction, Fukui University, *2 Department of Education, Osaka Kyoiku University, *3 Okayama University Medical School, *4 Director, Maruyama Hospital, *5 College of Liberal Arts, Kyoto University, *6 Swedish National Bord of Occupational Safety and Health |
Keywords
Tennis elbow, epicondylitis, tennis rackets, physiological effects