Body Control Method with Ancient Japanese Martial Arts (summary)
Lecturer: Hirohisa Wakita
This lecture explained the following facts to the participants. 1) The relationship between the body structure and quick movements. 2) Increase of the horizontal component force in making advancing motion in comparison to the conventional "kicking action", achieved by the utilization of the "relaxing action" in which the gravitational force integrated by releasing of tension from muscles decreases the active quantity of the gastrocnemius muscle, and the resulting reduction of time required for the action. 3) On the "landing" phase of walking motion, the "relaxing action" uses less of both braking and driving forces of the horizontal component force and shorter ground contact time, in comparison to the "kicking action". 4) In "responsive" movements, the "relaxing action" can respond to more various situations than the "kicking action", since it enables faster start of action while allowing slower action of muscle. 5) When lifting heavy objects, the "parallel cross action (lifting while relaxing knee joints)" allows faster angular velocity and places less load on shoulder joints in comparison to "hinge action (lifting only with shoulder joints)". 6) In "pushing" movements, utilizing "relaxing action" would add the body weight to the direction of movement by loosening muscle tension. With the addition of the muscle activity through the stretching reflex, it is capable of producing 1.6 times more advancing power compared to the "kicking action". 7) As lectured before, a cry can make the brainstem produces noradrenaline, which increases the maximum muscle strength and shortens the response time. In conclusion, movements that utilize the gravity through relaxing body parts put less loads on muscles and make the action quicker and more effective.