著者

坂本 将基 高柳 暁斗 安東 大輔

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.69, pp.1-16, 2024 (Released:2024-02-06)

参考文献数

28

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This study investigated the characteristics of visual behavior in skilled kendoists while judging the validity of strikes. A total of 19 expert and 19 novice kendoists were asked to judge the validity of strikes for men (head armor), do (side trunk covered by a stomach and chest protector), or kote (lower forearm covered by a gauntlet). Simultaneously, the participants' eye movements were recorded at 30 Hz, and the location at which their gaze was directed was identified. Additionally, the pupil area was calculated for each frame. Both expert and novice kendoists focused on the striker's shinai (bamboo sword) during the phase from 900 ms to 600 ms before striking, and on the site struck during the phase from the moment of striking to 300 ms after striking. However, during the phase from 600 ms before the strike to just before the strike, the experts tended to switch their gaze from the strikefur's shinai to the striking site earlier than the novices. Furthermore, the pupil areas of the experts were correlated with their years of experience in judging the validity of a strike to the men. The gaze behavior specific to expert kendoists, such as observing the striking area during the phase just before striking while exhibiting intense scrutiny, may be related to their superior ability to judge the validity of strikes.

著者

井福 裕俊 中山 貴文 坂本 将基 齋藤 和也 小澤 雄二 福田 晃平 中村 朱里

出版者

熊本大学

雑誌

熊本大学教育学部紀要 (ISSN:21881871)

巻号頁・発行日

vol.66, pp.267-272, 2017-12-19

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The purpose of the present study was to classify standing posture of the upper grade elementary school children in the second sexual stage into five types according to Kendall's method, and to clarify factors affecting those postures by using seven muscle strength or flexibility tests. A total of 196 children (104 boys, 92 girls) were analyzed. Only 22% of children were a good posture even if the ideal and military postures were combined, whereas a bad posture, i.e., kyphosis-lordosis, flat-back and sway-back postures, accounted for 78%. The deviation of the body's center of gravity was significantly shorter in the good pasture than in the bad posture. When principal component analysis was applied to the data for seven muscular strength or flexibility tests, military posture had high overall evaluation of muscular strength and flexibility and kyphosis-lordosis posture was lower, whereas ideal posture was mainly held by muscular strength and flexibility of lower body and flat-back posture was mainly held by those of upper body. These findings suggest that it is necessary to improve muscle strength and flexibility in order to improve the bad standing posture of upper grade elementary school children.

著者

遠藤 隆志 中島 剛 坂本 将基 塩澤 伸一郎 小宮山 伴与志

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.55, no.2, pp.269-278, 2006-04-01 (Released:2007-05-10)

参考文献数

38

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It has recently demonstrated that central fatigue during sustained maximal voluntary contraction (MVC) progresses faster in the presence of delayed onset muscle soreness due to eccentric contractions than in normal states (Endoh et al., 2005). However, it remains to be clarified whether these findings are related to muscle damage or muscle pain induced by eccentric contractions. The present study investigated which factor plays a more critical role in the earlier onset of central fatigue during sustained MVC with muscle pain induced by injecting hypertonic saline. Ten healthy male right-handed subjects (age, 21~32 yrs.) were asked to perform brief MVCs (~3 sec) before and after injection of isotonic saline (0.9%, 1.0 ml, ISO) or hypertonic saline (5.25%, 1.0 ml, HYP) into the left biceps brachii. The subjects then performed 1 min MVC (fatigue test) with isometric elbow flexion was done in ISO or HYP condition or intact control condition (CON). During these contractions, transcranial magnetic stimulation was delivered to the contralateral motor cortex to evaluate voluntary activation (VA), the motor evoked potential (MEP) and electromyographic (EMG) silent period (SP). Ratio of root mean square of the EMG and elbow flexion force (EMGrms/F) was also measured.The peak pain induced by the injection of HYP was significantly higher than that of ISO (p<0.01). There was no significant difference in either the maximum size of the M response or the twitch force between ISO and HYP (p>0.05). However, during the brief MVCs, both maximal force (p<0.01) and VA (p<0.05) for HYP were significantly decreased compared to those for ISO. During the fatigue test, although MVC, VA, MEP and SP were significantly altered (p<0.05~0.01), there was no significant difference among CON, ISO and HYP (p>0.05). There was no significant difference in EMGrms during the fatigue test (p>0.05).These results suggest that peripheral force-producing capacity remained intact after the injection of ISO and HYP during sustained MVC, and that progression of central fatigue during sustained MVC was less affected by the increased group III and IV afferent activity induced by HYP.