313 テニスラケットのストリング性能論1 : パワー,コントロール,打球感と性能の寿命に関する考察(テニス・あん馬) 313 Practical String performance theory 1 of the tennis racket : Power, Control, Feel and Performance Life
There has been no question that some strings do provide a better grip than others, but that did not guarantee that the ball will produce more spin. Furthermore, experiments with hand-held rackets has been needed to solve the difficult question of how players can tell the difference between different strings when laboratory tests indicate that they should play the same. The previous paper performed an experiment measuring the spin rates of used, notched strings in both their natural condition and after applying a lubricant to the string intersections to facilitate tangential string movement. It found that the lubricated notched strings produced 30% more spin than the unlubricated notched strings. The lubricant materials are effective to the notched strings, because the lateral movement and snap-back of the main strings increase spin. It also showed that the more spin results in the reduction of shock vibrations of the wrist joint during impact. Furthermore, it was shown that the used natural gut with notches decrease 70 % of spin rate compared to the new natural gut without notches in the another experiment, which has remained to be seen whether the same results will be obtained. Recently, International Tennis Federation researchers reported that the same movement that was observed with lubricated strings occurs with copoly as well. Copoly strings-slippery and stiff-generate more spin not because of more friction, but because of less. The old argument was that the better the grip between the strings and the ball, the more spin we would get, but that was not true. Many experiments has started to investigate whether the lateral movement and snap-back of the main strings increase spin, which strings generate the most spin, and so on. The research has also started to investigate the effect of a inter-string friction upon the main strings movement against the cross strings. Furthermore, the research has started to investigate how tennis strings "Go Dead". This paper clarified a mechanism for impact that is able to account for the wide range of string performance seen in the literature.
- シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集
シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集 2013(0), _313-1_-_313-10_, 2013