CONTROLLING IN BROAD JUMP
- VernacularTitle:跳躍動作の調整
- Author:
YURI KAWAHARA
- Publication Type:Journal Article
- From:Japanese Journal of Physical Fitness and Sports Medicine
1973;22(3):101-110
- CountryJapan
- Language:Japanese
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Abstract:
Our interest is to know the learning process of skillness, because more needed to apply the optimum muscle power rather than maximum one in our daily life. The experiment is so simply designed that subjects are only required to land just correctly at the marked line by a bound jump. The width by jumping to reach is only distance of 1/3 body height of each individual.
The jumpings are done in 3 ways : (1) voluntary take off, (2) take off with buzzer signal, (3) jumping with blindfold.
As subjects served boys and girls ranging from 6 to 21 years of age. Distances between maked line and landing point, and times taken by motions are measured, through the electric system with a strain guage which is attached to taking off and landing boad.
The results are shortly concluded as follow ;
(1) In more aged subjects make smaller gaps, which are given as the names of algebraical sum of absolute value of distance from maked line. The subjects of over 15 years of age landed always within small gaps.
(2) Subjects of over 15 years of age take longer time for knee joint extention. In younger subjects (i, e, younger than 15 years of age), time of knee extention is rather shorter, however, they take longer time for just sinking which is accompanied with knee extention.
(3) The jumping action is done in the series of motion of just sinking and extending the knee joint.
Correlationship between knee extention time and just sinking time is significant (r=0.569**), in the subjects of 18-21 years, however no correlationship is obtained in 6-11 years of age.
(4) Jumping with blindfold takes longer distance. The visual feedback seems to take major part in controling. However both ratio of knee extention per time of just sinking in the two ways of jumping i, e, voluntary jumping with open eye and with blindfold is almost same.
(5) In the case of taking off with buzzer signal, subjects incline to land further than voluntary take off. This gives us the suggestion that buzzer sound increases in the excitation on reticular activationg system. Poor coordination in young individuals is likely due not only to lack in cortical realization of motion pattern but to rough synapting of spinal and cortical circuit.
