RESUMEN
In Kendo, there is no consensus as to which hand should produce more pressure when attacking the opponent with the bamboo sword, let alone how to teach the pressure distribution during coaching. There is the theory that a Kendo attack can be divided into five phases, which has not entered the coaching practice, either. The aim of this study was to measure the grip pressure during Kendo attacks, investigate the pressure distribution between the two hands, and find evidence for the existence of the alleged five attack phases. We instrumented a bamboo sword with grip pressure sensors and investigated the grip pressure in 23 participants. In all attack targets and in both hands, the pressure across all attack phases was significantly different. In general, the left-hand pressure was consistently and significantly higher than the right-hand one, across all five attack phases, for the hand, head, and flank attack targets. The surprising exception was the throat target with only two attack phases, the strike phase of which showed a greater pressure in the right hand. Across all participants, the left-hand pressure was greater in 60.22-100% in any phase of the four attack targets, except for the strike phase of the throat target. Through these results, we could verify the effect of the teaching customs in Kendo, as well as provide first-time evidence of the existence of the five attack phases.
Asunto(s)
Mano , Artes Marciales , Humanos , Lateralidad Funcional , Fuerza de la ManoRESUMEN
A high-performance liquid chromatographic (HPLC) analysis of human serum albumin (HSA) using an ion-exchange (DEAE-form) column shows three components: The principal component corresponds to human mercaptalbumin (HMA); the secondary to nonmercaptalbumin (HNA), having mixed disulfide with cystine (HNA[Cys]), or oxidized glutathione (HNA[Glut]); and the tertiary to HNA, oxidized more highly than mixed disulfide. The purpose of the present study is to clarify the effects of strenuous exercise load on HMA--><--HNA conversion (i.e., dynamic change in redox state) of HSA from elite kendo athletes (n=30; 20.0+/-1.1 years old). They participated in an intensive kendo training camp for 5 d. The mean value for the HMA fraction (f[HMA]) of kendo athletes after camp (62.8+/-2.4%) was significantly lower than before camp (71.9+/-3.7%) (p<0.0005). In contrast, the mean value for f(HNA-1) (i.e., f[HNA(Cys) and HNA(Glut)]) after camp (34.2+/-2.1%) was significantly higher than before camp (25.7+/-3.7%) (p<0.0005). These results suggested that strenuous physical exercise markedly increased the oxidized albumin level in extracellular fluids during the intensive training camp.