1986 年 18 巻 3 号 p. 24-29
The purpose of this study was to investigate the characteristics of displayed force by left fingers on the handle of“shina-i” (fencing stave used in “kendo” ) in kendo (Japanese fencing) while hitting an opponent's face guard or hand armor from the position of the “shina-i” held above the head with left hand and supported ligthly with right hand. The present authors recorded the changes in left elbow joint angle, each force of left index, middle, ring and little fingers exerted on the handle of “shina-i” in three male adult who were skillful at hitting especially from the position of the “shina-i” held above the head. The following results were obtained.
1. Observing from the changes in left elbow joint angle, the subject hit the opponent's faceguard or hand armor, fully extending his left elbow joint. Each goniogram obtained in ten trials showed almost the same pattern in each technique (“men” or “kote”).
2. Left little and ring fingers showed peak force at the point of time of 0.11-0.12 seconds prior to the moment of hitting the opponents, accompanying speedy extension of its elbow joint, in each technique in all subjects. On the contrary to this, the index finger's force began to increase from the moment when the little and ring fingers showed peak force, and it showed peak value just about at the moment of hitting the opponent. The middle finger's force increased at the same time or just after the display of force in little and ring fingers. This first peak value was followed by the second peak one. Therefore, the pattern of displayed force in middle finger showed the intermediate aspect between those of little, ring and index fingers'.
3. When each peak force value was expressed as a percentage of maximum strength of each finger, the little and ring fingers' showed 139-202%and 100-120%, respectively, in technique of “men.” In technique of “kote,”the little and ring fingers' showed 181-240% and 95-105%, respectively.