テニスの筋疲労と筋痙攣に関する一考察

To throw some light on the relationship between the muscle cramp and muscle fatigue/muscle strength, three types of measurement of muscle strength, which were contractions of isokinetic-concentric, isokinetic-eccentric and isometric, were measured before and after the load exercise with the muscle of quadriceps, at which portion the muscle cramps break out usually and frequently during tennis competition. The following results have been obtained. 1) The reducing rate of the isokinetic-eccentric contraction strength at fatigue is largest among three types of strength and the deference was 233.7(N) (n : 6, s.d. : 94.5) and of significance (p<0.01). 2) On the difference of the reducing ratio with the fatigue between the isokinetic-concentric muscle contraction strength and the isokinetic-eccentric muscle contraction strength, the eccentrics reduced at 13.2(%)(n : 6, s.d. 9.68) of significance (p<0.05) and was larger than the concentric contraction. Developing upper results and considering that the eventual characteristic of tennis plays like a lot of repeated and continuous explosive dash-and-stop and dash toward reverse or other directions would cause the muscles of quadriceps and gastrocnemius for an overload of eccentric contraction which is most influenced by the fatigue, it can be mentioned that tennis has a lot of characteristic and inevitable load to the muscles of quadriceps and gastrocnemius, and more, it can be pointed out a certain cause that the eccentric muscle contraction is easily and greatly influenced by the continuous and explosive exercise leading to the fatigue and to the muscle cramp of quadriceps and gastrocnemius of some tennis players. Therefore both of the muscle strength and endurance training to the high frequency portion of muscle cramp will prevent from the muscle cramp. And in the present study, a few pieces of information are suggested on the relationship between the fast twitch muscle and the cramp.