Effect of rebound jump ability on running long jump ability: In the sixth graders of elementary school

The purposes of this study were to investigate the effect of rebound jump (RJ) ability on running long jump ability in elementary school children, and to clarify RJ ability and takeoff characteristics in athlete children. The subjects were 53 boys and 60 girls who were sixth-graders at elementary school and 5 boys and 4 girls who were experienced athletes (Athlete group). They were filmed in the takeoff phase, and RJ ability (RJ-index=RJ-height/contact time) was measured. The students were dividing into three groups based on RJ ability: Excellent group, Medium group and Poor group. Measured variables during takeoff were compared among these three groups and the Athlete group. The main results were as follows:1) Among the students, the Excellent group for both boys and girls showed a longer jumping distance, and higher touchdown and takeoff velocities, respectively, than the other groups. Moreover, the Excellent group showed a shorter contact time, greater vertical average force and achieved a higher vertical velocity at takeoff, although there was no significant difference in the decrease in horizontal velocity among the three groups, for either boys or girls.2) The athlete group, both boys and girls, showed a better RJ-index and RJ-height than the Excellent group, respectively. Moreover, the athlete group showed a longer jumping distance, higher touchdown and takeoff velocities, a shorter contact time, a greater vertical average force and a higher vertical velocity at takeoff than the Excellent group, respectively.It is concluded that RJ ability in sixth graders of elementary school affects approach velocity, jumping distance, and vertical velocity at takeoff.