著者
桜井 伸二 池上 康男 矢部 京之助 岡本 敦 豊島 進太郎
出版者
社団法人日本体育学会
雑誌
体育學研究 (ISSN:04846710)
巻号頁・発行日
vol.35, no.2, pp.143-156, 1990-09-01
被引用文献数
8

Many joint actions are involved in the throwing motion of a fastball pitch; therefore, two dimensional (2-D) procedures are insufficient for analyzing the throwing motion. In this study,three dimensional (3-D) high-speed cinematography was used to record fastball pitches of varsity baseball pitchers. Two small reference sticks were fixed on the hands and forearms of the throwing arm of the subjects to detect their movements.The direct linear transformation (DLT) method was used for 3-D space reconstruction from 2-D images filmed by two from 2-D images filmed by two phase-locked cameras (200 frames/s).The throwing arm has seven degrees of freedom of joint motion except in the fingers; three for the shoulder, one for the elbow, one for the radioulnar, and two for the wrist. Following seven joint angle changes corresponding to all these degrees of freedom were obtained throughout the pitching motion. 1) horizontal abduction/horizontal adduction angle at the shoulder joint, 2) abduction/adduction angle at the shoulder joint, 3) internal rotation/external rotation angle at the shoulder joint, 4) flexion/extension angle at the elbow joint, 5) pronation/supination angle at the radio-ulnar joint (forearm), 6) radial flexion/ulnar flexion angle at the wrist joint, 7) palmar flexion/dorsi flexion angle at the wrist joint. The results showed that horizontal adduction and internal rotation of the shoulder,extension of the elbow, pronation of the forearm, and palmar flexion of the wrist were the important joint actions for fastball pitching in baseball. Preliminary to these motions were motions in the opposite direction; e.g., horizontal abduction and external rotation of the shoulder,flexion of the elbow, supination of the forearm, and dorsi flexion of the wrist were detected.These motions in the opposite direction would be useful to extend the range of the motion in each joint angle. The results also appear to be connected to intrinsic muscle propertios, that greater power can be exerted during shortening of the muscle when it is stretched just before the shortening action.
著者
木下 秀明
出版者
社団法人日本体育学会
雑誌
体育學研究 (ISSN:04846710)
巻号頁・発行日
vol.17, no.6, pp.357-366, 1973-03-25

明治24年に設立された日本体育会は, 大正3年の経済的危機にいたるまで, 唯一の民間体育団体として, 社会体育と学校体操指導者養成に多大の貢献をしている. その創立期から最盛期を経て衰退期にむかう間の本会の活動についての概観である. 1.退役下士官日高藤吉郎による日本体育会の創立とその概要 2.創立期の活動である体育場, 運動会, 体操練習所, 体育講演会, 体育雑誌の刊行についての概説 3.閑院宮を総裁とし社団法人となって, 各地に支会を置いた日本体育会の発展状況 4.最盛期の活動である体操学校, 夏期講習会, 模範体操場とそのクラブ, 運動場開放, 内国勧業博覧会参加, 兵事講習会など中央での概況と地方支会の活動状況の数量的一覧 5.日本体育会の国際的地位の例示 6.日本体育会の衰退の概観