For the purpose of determining the technical characteristics of the striking motion from Nito-no-Kamae in Kendo, we measured the impact force of the striking motion with DAITO (long-shinai) and SHOTO (short-shinai) using as subjects three male university teachers, who are majoring in Kendo, and analyzed the data by a motion analysis system with a video tape recorder. For comparison, similar measurements were performed on the striking motion with the two-handed striking motion from Chudan-no-Kamae and the one-handed striking motion from Jodan-no-Kamae. The following results were obtained from a examination of the data. 1. The maximum downward magnitude of the impact force and the downward impulse value of three kinds of the striking motions with SHOTO from Nito-no-Kamae were greater than that of the two-handed Shomen striking motion from Chudan-no-Kamae. However, the maximum downward magnitude of the impact force and the downward impulse value of two-kinds of striking motion with DAITO from Nito-no-Kamae were smaller than that of two-handed Shomen striking motion from Chudan-no-Kamae. 2. The impact time of all the striking motion from Nito-no-Kamae were shorter than that of the two-handed striking motion from Chudan-no-Kamae. 3. The motion of shinai in the striking motions from Nito-no-Kamae were chiefly made using the left elbow and the left wrist. 4. The angular velocity of shinai immediately before impact using Hikikote striking motion with SHOTO of Nito-no-Kamae was the largest, and that using the Shomen striking motion with DAITO of Nito-no-Kamae was the smallest.
A study was conducted to investigate the characteristics of motor control from the view points of stretch reflexes and premotor time in kendo players as compared with sprinters and non-athletes. A DC torque motor was used to provide a sudden muscle stretch stimulus at the right wrist flexor. The subjects were asked to do a reaction movement during wrist flexion to the muscle stretch. We measured the modulation of long latency stretch reflex (M2 component) and premoter time during reaction movement by the analysis electromyogram recorded from the wrist flexor. The main results were as follows 1) The premotor time in kendo and sprinter groups were significantly shorter than in non-athlete group.And there wasn't significant difference between kendo group and sprinter group. 2) In all subjects, the amplitude of M2 component increased during flexion reaction movement. The increasing rate of M2 amplitude in Kendo group was significantly larger than in other groups, and it in sprinter group was significantly larger than in non-athlete group. 3) When the kendo players were classified into two groups according to kendo performance, the increasing rate of M2 amplitude in the higher performance group was significantly larger than in the lower performance group, but the difference in premotor time between the two groups was very insignificant. From these results, it became clear that the kendo player can effectively control the amplitude of long latency reflex for reaction movement as well as he can do a quick reaction, and suggested that a degree of change in M2 amplitude from wrist flexor reflects the characteristics of motor control in kendo players.
The purpose of the present study was to compare isokinetic muscle strength of shoulder, hip, knee and trunk at varying speed between elite and student in kendo and normal subjects. Subjects were 7 elite in all Japan kendo championship whose average age was 36.1±4.3 years and 6 student kendo player whose average age was 20.2±0.4 years and 20 normal whose average age was 35.3±2.8 years. An isokinetic dynamometer (Cybex II) was used to measure the peak torque generated during shoulder extension &flexion, shoulder internal & external rotation, hip extension & flexion, hip abduction & adduction and knee extension & flexion at three different speed (60,180,240°/sec.). And the trunk extension flexion unit was use to measure the peak torque generated during trunk extension & flexion at three different speed (60,120,150°/sec.). These result were obtained: I) Eite kendo players were superior in isokinetic strength of shoulder extension, shoulder external rotation, hip extension and hip adduction at these condition,2)nevertheless elite and control group of knee extension & flexion was not significant.3) In the ratio of. antagonist to agonist on upper and lower limb, elite kendo players were superior in extension/flexion of both shoulder, extension/flexion of hip of right side internal/external rotation of both hip.The ratio of knee extension /flexion in elite was higher in only 180°/sec. of right side and 240°/sec. of left side than control. Elite on extension/flexion ratio of trunk was not significant. These results suggested that developments of strength of elite kendo player were specifically different the agonist and antagonist muscle group by kendo training.