A longitudinal study on development of 50m sprinting performance for junior high school students

[出版社版]This research investigated through a first grade at a junior high school child and, until third grade time after two year, analyzed sprinting performance for 77people (43boys and 34girls). They were filmed in VTR picture during 50m sprinting. Using the VTR pictures, we calculated average speed, step frequency, step length and rate of speed diminishing successively. The results obtained were as follows: 1. It can be judged that the boy junior high school student has remarkably improved the sprinting velocity in the passing age because of the increase of the step length. And, it is thought that the girl is not seen an increase at the sprinting velocity, and has stagnated by a value in the first grade of junior high-school. 2. As for the boy, 50m dash quickened in year of passing because a maximum speed had remarkably increased. On the other hand, for the girl the 50m dash has not improved in year of passing because of no so much increase of a maximum speed, and the latter section speed fell at especially three time of year. 3. It is thought that the reason for the student with high average sprint velocity is that a maximum speed is high, and the rate of the speed diminishing successively is low about the boy, and is that so unrelated to the rate of the speed diminishing successively but a maximum speed section is high about the girl for each school year. 4. Though the boy had become long in the passing age in the distance that reached at the highest sprint velocity, the girl was too changeless in the passing age