著者
宮元 章次 石河 利寛 北村 虎雄 押川 紘一郎
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.44, no.6, pp.493-499, 1999

The present study was conducted to examine the effect of relatively low-impact exercise on declining bone mineral density, which is a cause of fractures in aged women. Twelve female participants aged 64-76 years before training began to practice gateball for 100-150 min every day, 4-6 days a week for four years. A control group comprised six women aged 66-75 years before training. Dual X-ray absorptiometry was used to measure body composition and bone mineral density (BMD). There were significant differences in BMD (femoral neck, Ward's triangle, trochanter, and lumbar vertebra) before training between the gateball group and the control group. BMD in the control group was below the threshold for increased danger of femoral neck fracture. The rate of change in BMD (femoral neck, lumbar vertebra) in the training group (-0.8% per year, -0.8% per year) was smaller than that in the control group (-1.2% per year, -1.1% per year), and each respective difference was significant, A significant increase was found in the rate of change in lean tissue mass in the training group (0.6% per year). Therefore regular low-impact exercise (gateball) can play an important role in preventing bone fracture in elderly women.
著者
藤田 善也 石毛 勇介 吉岡 伸輔 竹田 正樹
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.13047, (Released:2014-01-23)
参考文献数
10

The purpose of this study was to evaluate the relationships between race performance and cycle characteristics in a 10-km classic-style men's cross-country ski competition. The subjects were competitors in the 89th Japan National Ski Championships. Skiing motions of the subjects on flat stretches (1.5 km and 6.5 km) and uphill slopes (1.7 km and 6.7 km) were videotaped using two high-speed cameras. Cycle characteristics were calculated based on measurement of hip displacement and cycle time. It was revealed that elite competitors (1) performed at high velocity at all measurement points, (2) reduced their velocity in the last half of the race, (3) achieved a high velocity in double poling and diagonal stride, (4) increased their cycle length and cycle rate when employing the double poling technique, and (5) increased their cycle length when employing the diagonal stride technique.
著者
松尾 知之 平野 裕一 川村 卓
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.58, no.1, pp.195-210, 2013 (Released:2013-06-08)
参考文献数
18

Expert players and/or expert coaches have a large stock of experiential knowledge, including knowledge of movement-related causality. We attempted to extract experiential knowledge of movement-related causality in baseball pitching from expert players and coaches with sufficient creditability. Verbal data collected in a previous study (Matsuo et al. 2010) using semi-structured interviews with four former professional baseball pitchers and seven expert baseball coaches were used for this study. The data had been categorized on the basis of a wide variety of coaching points. A matrix of co-occurrence based on the verbal data was used to calculate the strength of association between pairs of categories. In the process of the calculation, we employed the matrix calculation utilized in the Dematel method to count indirect associations. The distances among categories, calculated on the basis of co-occurrence probability, were used to assess the creditability of the verbal data. The categories were mapped into three-dimensional space using the least squares method, based on the distances. The associations of categories were extracted as highly trustworthy when the root mean squared error between the original distances and the mapped distances was below 10%. Among the extracted associations, the direction of causality was added to the associations that expressed the causality explicitly among the verbal data. The major selected causalities were as follows:1)  Moving forward before placing weight on the pivot foot sufficiently opens the trunk earlier and leads to insufficient weight being placed on the stride foot.2)  An inadequate take-back action, especially excessive horizontal abduction and elbow extension, limits the flexible arm movement around throwing-side ear and leads to lower shoulder abduction. In addition, it makes the trunk open earlier.3)  Excessive lead elbow extension during the stride phase makes the trunk open earlier. How the lead-arm is pulled towards the trunk also affects trunk rotation.4)  Bending the neck at any point leads to inadequate trunk rotation.
著者
稲葉 智彦 向井 直樹
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.55, no.1, pp.147-155, 2010 (Released:2010-07-20)
参考文献数
20

When a unilateral transfemoral amputee performs sprinting, alternation between the sound limb and the prosthetic limb causes asymmetrical motion. One of the causes of the asymmetrical sprinting performance is that the knee joint of the prosthetic limb does not flex easily due to strong flexion resistance in order to prevent giving way during the landing by extension delay of the shank after flexion in the swing phase. This study examined whether the prosthetic limb performs the same motion as the sound limb working with the movements of the hip joint and other areas by setting the knee joint to allow easier flexion when relaxing the flexion-and-extension resistance of the knee joint in the swing phase. Moreover, when possible, we also examined whether this allows more rational motion than during sprinting when the flexion resistance of the knee joint is set strongly. The composition of the prosthetic limb used for the trial was an IRC (Ischial Ramal Containment) suction socket, high-activity hydraulic knee joint (model 3R55; Otto Bock, Duderstadt, Germany) in which the flexion-and-extension resistance was relaxed, in combination with an energy-storing prosthetic foot for running (model Sprinter; Otto Bock, Duderstadt, Germany). Sprinting was performed by a unilateral transfemoral amputee using this prosthetic limb after the subject had learned how to sprint while using it. Sprinting performance was filmed (30 fps) with a video tape recorder (DCR-PC101 NTSC, Sony Corporation, Tokyo, Japan), and we compared the motion of the prosthetic foot and the knee joint angle with the motion of the sound limb. Moreover, the motion was also compared with that during sprinting when the flexion-and-extension resistance of the knee joint was set strongly. As a result of the relaxed setting of the prosthetic knee joint, it was shown that the prosthetic limb performed the same motion as a sound limb without giving way at landing by extension delay of the shank of the prosthetic limb during the swing phase. Moreover, it was shown that this setting facilitates more rational motion than that during sprinting with a stronger setting for the flexion resistance of the knee joint.