著者

国正 陽子 佐野 加奈絵 久野 峻幸 牧野 晃宗 小田 俊明 石川 昌紀

出版者

一般社団法人 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.66, 2015

著者

新井 彩 石川 昌紀 浦田 達也 国正 陽子 佐野 加奈絵 田中 ひかる 伊藤 章

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.64, no.1, pp.165-172, 2015-02-01 (Released:2015-01-25)

参考文献数

23

被引用文献数

2 1

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The purpose of the present study was to examine the importance of the agonist muscle activity of the post-impact 30 ms phase during drop jump (DJ) for effective rebound performance by comparing those of sprint runners and swimmers. The eight sprint runners (SPRINT) and twelve swimmers (SWIM) were participated in this study. They performed DJ from a 0.3-m height box with maximal rebound efforts. Electromyograms (EMG) of the lower leg muscles (medial gastrocnemius [MG], soleus [SOL] and tibialis anterior [TA]), and vertical ground reaction force together with kinematic data were measured simultaneously during DJ. In addition, the onsets of fascicle stretching of the MG and SOL muscles were measured by using high-speed ultrasonography (521Hz) during DJ. The onsets of the fascicle stretching of SOL during DJ were not significantly different between SPRINT and SWIM (15 ± 7 ms and 16 ± 6 ms, respectively). During DJ, SPRINT showed onset of the SOL EMG before the ground contact (-26 ± 19 ms). Meanwhile, SWIM showed the onset of the SOL EMG after the ground contact of DJ (16 ± 19 ms). These results suggest that the SOL muscles for SWIM cannot be fully-activated during the braking phase. Consequently, the rate of force development during the braking phase of DJ and subsequently rebound height could be reduced in SWIM.

著者

牧野 晃宗 岩崎 正徳 国正 陽子 久野 峻幸 佐野 加奈絵 村元 辰寛 村上 雷多 神﨑 浩 小田 俊明 石川 昌紀

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.61, no.2, pp.639-649, 2016 (Released:2016-12-14)

参考文献数

18

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One of the most frequent injuries in Kendo athletes is Achilles tendinopathy in the left leg, for example Achilles tendon rupture. However, preventive approaches for Achilles tendinopathy in Kendo athletes have not been well considered. Therefore, the purpose of the present study was to examine differences in the architectures of the gastrocnemius muscle and Achilles tendon in relation to kendo training experience, and to examine the mechanical properties of the Achilles tendinous tissues (AT) in Kendo athletes in order to clarify why Achilles tendinopathy occurs in the left leg. Sixty-five Kendo male athletes with different periods of kendo training experience and 20 healthy male control subjects participated in this study. The architectural properties of the medial gastrocnemius muscle (MG) and Achilles tendon in both legs were measured using ultrasonography. In addition, 20 expert Kendo male athletes and healthy male controls pair-matched with the kendo athletes for body height and body mass were examined for their AT mechanical properties during passive dorsiflexion of both legs. The differences in the cross–sectional areas of the Achilles tendon and MG muscle between the left and right legs were greater in Kendo athletes with longer experience. Especially, the expert kendo athletes had lower AT stiffness and Young's modulus in the left leg than did the control subjects. These results suggest that kendo leads to specific Achilles tendon and muscle adaptation. These specific adaptations of the MG fascicles and AT may be one of the risk factors for Achilles tendon rupture in Kendo athletes.

著者

上野 薫 前濱 良太 国正 陽子 牧野 晃宗 佐野 加奈絵 貴嶋 孝太 Komi Paavo V 石川 昌紀

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.67, no.6, pp.383-391, 2018-12-01 (Released:2018-11-21)

参考文献数

38

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The purpose of the present study was to examine characteristics of muscle anatomical cross-sectional area (CSA) for different regions from proximal to distal parts of each muscle of the hamstring muscles in high-level sprinters, and to examine the relationship with those and the sprint performance. The CSA of the semitendinosus (ST), semimembranosus (SM), biceps femoris long head (BFL) and biceps femoris short head (BFS) at the four different region of hamstring muscles for twenty sprinters (SPRINT) and twenty healthy male control subjects (CTRL) were measured by using B-mode ultrasonography. The measured regions were divided into four parts from proximal to distal parts (PRO1, PRO2, DIS2, DIS1). The results clearly showed that absolute CSA values in distal parts for all muscles together with PRO2 in ST were greater in SPRINT than in CTRL. When relative CSA values to the entire hamstrings muscles in each region were compared, only relative CSA at PRO1 in ST was greater in SPRINT than in CTRL, conversely, that at proximal regions in BFL and distal regions in BFS were smaller in SPRINT. In the relationships with sprint performance, the CSAs at PRO1 and PRO2 in ST and at PRO1 in SM were only related negatively. These results suggest that distal parts of hamstring muscles for SPRINT may be characteristics for sprint runners. However, the movements related to the specific hypertrophy (PRO1 and PRO2 in ST, PRO1in SM) may play important roles of the improvement of their sprint performance.