著者
吉田 和人 山田 耕司 玉城 将 内藤 久士 加賀 勝
出版者
Japan Society of Physical Education, Health and Sport Sciences
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
vol.59, no.1, pp.227-236, 2014
被引用文献数
1

The rotation speed of the ball spin has been considered a key factor in winning table tennis matches. This study quantified the rotation speed (rotations per second: rps) of service balls delivered by quarter-finalists in the 2009 World Table Tennis Championships. Ball services were recorded during the quarter-finals of both the men's and women's singles, involving 4 matches and 8 players per gender, using a high-speed video camera (1000 fps) for calculation of the rotation speed, and a standard video camera (30 fps) for distinguishing players and aces (including those touched by the receiver). Eventually, the rotation speeds of 329 services were calculated, and these ranged from 13.7 to 62.5 rps. For men, 50-60 rps was the most frequent (40.0%) range of the rotation speeds, while for women, the corresponding range was 40-50 rps (43.8%); the average (±SD) rotation speed was significantly greater for men than for women (46.0±9.0 vs. 39.2±9.3 rps, p<0.001). The fastest rotation speed was 62.5 rps for both genders. Chinese men produced a slower rotation speed than did other men (43.5±8.9 vs. 51.0±6.8 rps, p<0.001). For women, however, the rotation speed was similar between Chinese players and the others (39.9±10.2 vs. 38.5±8.2 rps). The rotation speeds of aces were scattered over a wide range of 37.0-58.8 rps for men and 27.8-62.5 rps for women, implying a weak association between aces and fast rotation. These pioneering data may help clarify some of the technical and tactical aspects of table tennis, and can be used to develop training and game strategies for successful performance.<br>
著者
加賀 勝 細谷 聡
出版者
日本武道学会
雑誌
武道学研究 (ISSN:02879700)
巻号頁・発行日
vol.26, no.3, pp.25-30, 1994-03-30 (Released:2012-11-27)
参考文献数
18

The purpose of this study was to clear mechanical characteristics of the Japanese bow, and find the energy transfer efficiency. The exeperiments were made by five classes of bows, arrows and strings heights. The potential energy(PE)was calculated on every bows.And the kinetic energy (KE)was calculated from shooting experiment according to arrows and strings heights.Then, the energy transfer efficiency was obtained on KE/PE X 100.The results were as follows:1, Relation between the drawing length and the drawing force shows a inverted S curve. This characteristic is constant regardless of the bow's strength and strings height.2, The potential energy is increased by the drawing length. The general tendency that the strong bow has high potential energy was evident.3, The minimum of the energy transfer efficiency lies on 15cm of the strings height in the experiment according to five classes strings height.4, In this study, the energy transfer efficiency is increased until 29g of the mass of arrow. And more than that, the energy transfer efficiency was decreased. It seems that there is a matching point of bow and arrow.
著者
細谷 聡 加賀 勝
出版者
日本武道学会
雑誌
武道学研究 (ISSN:02879700)
巻号頁・発行日
vol.35, no.2, pp.11-18, 2002-11-30 (Released:2012-11-27)
参考文献数
12

Since a Japanese-style bow is very complicated in both shape and structure, torques in horizontal and sagittal planes regarding grip must be applied to hit the target. This study biomechanically investigated the relationship between left forearm muscular activities and torques in horizontal (called the “NEJIRI” technique) and sagittal planes (called the “UWAOSHI” technique)regarding grip.Surface EMGs of four muscles (extensor carpi radialis longus, extensor digitorum, extensor carpi ulnaris, flexor carpi ulnaris) were collected from ten male subjects shooting arrows. The habit of the motion of drawing the bows that is called “BIKU” was measured incidentally from the experiment. As a result of statistics analysis, extensor digitorum and extensor carpi ulnaris muscles had positive relationships to the torque in the horizontal plane (“NEJIRI” technique). On the other hand, extensor carpi ulnaris and flexor carpi ulnaris muscles had positive relationships to the torque in the sagittal plane (“UWAOSHI” technique). It is suggested that extensor carpi ulnaris is complicatedly controlled to accomplish the operation of “TENOUCHI”, the shooting technique, in KYUDO.
著者
加賀 勝
出版者
日本武道学会
雑誌
武道学研究 (ISSN:02879700)
巻号頁・発行日
vol.19, no.2, pp.45-46, 1986 (Released:2012-11-27)
参考文献数
6
著者
吉田 和人 山田 耕司 玉城 将 内藤 久士 加賀 勝
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.28, no.1, pp.65-74, 2014-11-20 (Released:2019-09-02)
参考文献数
16
被引用文献数
1

A notational analysis of 12,428 rallies in 149 singles matches at the London Olympic Games was conducted to clarify the characteristics of world-class rallies in table tennis. The number of shots played per rally, which was the sum of a correct service and correct returns, was measured. And the winning ratios of server and receiver were determined by the number of shots played per rally (Odd numbers indicate the server won the point, even numbers indicate the receiver won the point). The playing styles of the players were classified into all-round types and defensive types (chopper type), and the types of matches were classified into 3 by the combination of playing styles as: all-rounder vs. all-rounder (AA type), all-rounder vs. defensive (AD type) and defensive vs. defensive (DD type). The numbers of shots and the two ratios, and relations to both gender and type of match were considered. The DD type was excluded from this analysis because there were too few measured data. As a result, the mode of the number of shots for men and women was 3 each. The maximums for men and women were 38 and 60, respectively. The minimum for men and women were 0 each. The mean number of shots for women was significantly larger than that for men for AD type (p<0.01), and that for AD type was significantly larger than that for AA type for both men (p<0.01) and women (p<0.001). The mean winning ratios for servers for both men and women for AA type and AD type were all at the same level at about 55%, which were significantly higher than those for receivers of about 45% (p<0.01). Additionally, the evaluation criteria for the mean number of shots in a match, and those for the winning ratios of a server and a receiver were proposed. It was suggested that these results could be valuable for table tennis coaching.
著者
加賀 勝 平田 和子 高橋 香代 清野 佳紀
雑誌
日本小児科学会雑誌 (ISSN:00016543)
巻号頁・発行日
vol.106, no.5, pp.655-664, 2002-05-01
参考文献数
19
被引用文献数
5
著者
吉田 和人 山田 耕司 玉城 将 内藤 久士 加賀 勝
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
pp.13068, (Released:2014-04-21)
参考文献数
19
被引用文献数
6 1

The rotation speed of the ball spin has been considered a key factor in winning table tennis matches. This study quantified the rotation speed (rotations per second, rps) of service balls delivered by quarter-finalists in the 2009 World Table Tennis Championships. Ball services were recorded during the quarter-finals of both the men's and women's singles, involving 4 matches and 8 players per gender, using a high-speed video camera (1000 fps) for calculation of the rotation speed, and a standard video camera (30 fps) for distinguishing players and aces (including those touched by the receiver). Eventually, the rotation speeds of 329 services were calculated, and these ranged from 13.7 to 62.5 rps. For men, 50-60 rps was the most frequent (40.0%) range of the rotation speeds, while for women, the corresponding range was 40-50 rps (43.8%); the average (±SD) rotation speed was significantly greater for men than for women (46.0±9.0 vs. 39.2±9.3 rps, p<0.001). The fastest rotation speed was 62.5 rps for both genders. Chinese men produced a slower rotation speed than did other men (43.5±8.9 vs. 51.0±6.8 rps, p<0.001). For women, however, the rotation speed was similar between Chinese players and the others (39.9±10.2 vs. 38.5±8.2 rps). The rotation speeds of aces were scattered over a wide range of 37.0-58.8 rps for men and 27.8-62.5 rps for women, implying a weak association between aces and fast rotation. These pioneering data may help clarify some of the technical and tactical aspects of table tennis, and can be used to develop training and game strategies for successful performance.
著者
渡部 昌史 加賀 勝 鈴木 久雄 高橋 香代
出版者
日本スポーツ教育学会
雑誌
スポーツ教育学研究 (ISSN:09118845)
巻号頁・発行日
vol.23, no.2, pp.113-122, 2003-12-31 (Released:2010-08-10)
参考文献数
36
被引用文献数
1

The objective of this study was to clarify the influences of sports activity in junior high-school athletes on bone strength and fractures. The subjects were 57 male junior high-school athletes aged from 13 to 15 years. They trained 120min, 6 times /wk. As an index of the bone strength, we measured the speed of sound of tibia (t-SOS) using Sound Scan 2000 Compact (Myriad Ultrasound System Ltd., Israel). The fracture rate was compared between the junior high-school athlete and control groups. The following results were obtained.(1) In the junior high-school athlete group, their t-SOS was significantly lower than control group.(2) The value of t-SOS demonstrated a negative correlation with the length of tibia/height ratio in the junior high-school athlete and control groups.(3) The value of t-SOS demonstrated a positive correlation with calcium intake from dairy products in the junior high-school athletes.(4) The junior high-school athletes showed a very high fracture rate. Particularly, the highest fracture rate (26.7%) was seen in the 13-year-old in the junior high-school athletes.These data will be useful for designing appropriate exercise programs to support the growth and bone mineral acquisition in the junior high-school athletes.