著者

坂口 将太 図子 浩二

出版者

一般社団法人 日本体育・スポーツ・健康学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.58, no.2, pp.599-615, 2013 (Released:2013-12-07)

参考文献数

27

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This study investigated the development of rebound jumping ability in preschool children. The subjects included 100 boys (2 years: 8, 3 years: 19, 4 years: 33, 5 years: 30, and 6 years: 10) and 80 girls (2 years: 11, 3 years: 22, 4 years: 21, 5 years: 18, and 6 years: 8). The measurements used were jumping height in counter movement jumping (CMJ), index (jumping height/ground contact time) of consecutive rebound jumping (RJ), foot length, shank length, Achilles tendon length, relative Achilles tendon length (Achilles tendon length/shank length), relative foot length (foot length/shank length) and calf girth as morphological characteristics. The main results obtained were as a follows.   1)  CMJ jumping height and RJ-index increased with age. Development of RJ-index depended on the increase in jumping height because ground contact time did not change even though jumping height increased with age.   2)  CMJ and RJ ability development types were classified into 3 groups according to ±1 SD of the residual of regression line with age in months (good, equal, and poor groups). For RJ ability, the number of equal groups decreased significantly after 50 months in boy and girls. In addition, for boys, the number of individuals in the good group increased significantly after 50 months, whereas for girls, the number of individuals in the poor group increased significantly after 50 months. No such changes were found in CMJ ability.   3)  RJ jumping height and ground contact time were compared among the 3 groups. The good group showed a significantly higher jumping height and shorter ground contact time than the other 2 groups. In addition, morphological characteristics showed no significant differences among the 3 groups.   These results suggest that the development of RJ ability differs from that of CMJ ability, and that the development difference in RJ ability begins to become evident in infants over 50 months. In addition, it is suggested that this difference is influenced by factors other than morphological characteristics.

著者

藤林 献明 坂口 将太 苅山 靖 図子 浩二

出版者

一般社団法人 日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.59, no.1, pp.175-188, 2014 (Released:2014-06-13)

参考文献数

15

被引用文献数

4

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The present study was conducted to examine the most effective takeoff movement for the Rebound Long Jump Test (RLJ test) under high-speed conditions. This test is designed to evaluate the ability to perform the ballistic stretch-shortening cycle movement for unilateral horizontal jump events on the basis of the RLJ index (RLJ index (m/s)=Jumping distance (JD (m))/Contact time (CT (s)). Subjects jump from a 0.1-m-high step to the ground after an approach run (falling jump), followed by jumping without interruption for as far as possible (propulsive jump). Eleven male college track-and-field athletes performed the RLJ test, and the RLJ index was calculated. On the basis of the average value of the RLJ index, the athletes were assigned to an upper level group (RLJ index>mean value) or a lower level group (RLJ index<mean value), and the takeoff movement of upper level group was considered the effective takeoff movement. The results suggested that it was important to minimize the rotation angle of the body, and to use a faster rotation velocity. This was achieved by 1) increasing the movement distance and velocity in the direction of the forward movement of the swing leg in the air, 2) minimizing the rotation angle of the foot and shank segment, and increasing that of the thigh segment during the initial phase, and 3) accelerating the rotation angle of the thigh segment again and swinging the swing-leg forward and up during the latter phase. These results suggest that the RLJ test and RLJ index provide a measure of the takeoff movement technique in terms of pre-rotation moment, the mechanism of rotation of the lower limb segment, and the swing moment of the swing leg.

著者

高橋 亜弓 中野 美沙 山元 康平 坂口 将太 大山下 圭悟

出版者

社団法人日本体育学会

雑誌

日本体育学会大会予稿集

巻号頁・発行日

vol.64, 2013

著者

坂口 将太 藤林 献明 苅山 靖 図子 浩二

出版者

日本発育発達学会

雑誌

発育発達研究 (ISSN:13408682)

巻号頁・発行日

vol.2014, no.62, pp.24-33, 2014-03-01 (Released:2014-05-05)

参考文献数

25

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The purpose of this study was to investigate the relationship between rebound jumping ability and running ability in preschool children. The subjects consisted of 166 preschool children (96 boys and 70 girls;age range:2.0-6.0 years). The measurements used were jumping height of counter movement jumping (CMJ), index (jumping height/ground contact time) of consecutive rebound jumping (RJ), 20-m running velocity (RV), step length (SL) and step frequency (SF). To exclude the effects of growth on running ability, dimensionless numbers:indices of running velocity (IRV), step length (ISL) and step frequency (ISF) were calculated. Results were as follows;1 ) CMJ jumping height, RJ-index, RV, SL, IRV and ISL increased with aging. 2 ) The IRV, ISL and ISF correlated with CMJ jumping height and RJ index. The coefficient correlation of RJ-index to increase with aging. 3 ) RJ height and RJ ground contact time correlated with flight time and ground contact time in the 20-m run. These results suggest that CMJ and RJ ability influence the development of running ability in preschool children.