21 0 0 0 OA 熟練者と未熟練者の比較によるクイックリフトトレーニング動作時における力発揮メカニズムの検討
- 著者
- 長尾 秀行 山田 洋 小河原 慶太 有賀 誠司 小金澤 鋼一
- 出版者
- バイオメカニズム学会
- 雑誌
- バイオメカニズム (ISSN:13487116)
- 巻号頁・発行日
- vol.23, pp.161-172, 2016 (Released:2017-08-01)
- 参考文献数
- 23
- 被引用文献数
- 1
本研究の目的は, 力発揮能力改善を目的としたトレーニングであるクイックリフト (以下QL) 動作時の力発揮特性とそのメカニズムを検討することである. 代表的なQLであるパワークリーンを対象に挙上重量が大きい者と小さい者各6名の動作分析の結果, 最大挙上重量が大きい者は, 下肢関節最大トルクとセグメント間のエネルギの流出入量が大きく, 特有の反動動作が見られた. さらに, 最大挙上重量が大きい者と小さい者各10名の筋電図分析と動作分析の結果, 挙上重量が大きい者と小さい者間の下肢関節伸展筋の筋活動度は同等で, 屈筋と伸筋の筋活動から推定した関節剛性と関節トルク立ち上がり速度は挙上重量が大きい者の方が反動動作の前後において大きな値を示した. このことから, QL時の大きな力発揮には下肢関節の剛性を巧みに制御し, エネルギ伝達の効率化を図る必要があることが示された.
- 著者
- 小畑 直之 長尾 秀行 三浦 智和
- 出版者
- 独立行政法人 日本スポーツ振興センター国立スポーツ科学センター
- 雑誌
- Journal of High Performance Sport (ISSN:24347299)
- 巻号頁・発行日
- vol.10, pp.74-84, 2022 (Released:2022-12-18)
- 参考文献数
- 23
This study aimed to identify the characteristics of snatch lift in top-class Japanese female weightlifters. The hypothesis was that lifters who are good at the snatch had lower barbell velocity in the 1st pull and longer heel contact time based on their weightlifting coaching points. Female lifters who competed in the 2021 All Japan Women's Weightlifting Championships were included in the study. Lifters who had a small difference in scores between the best attempts in snatch and clean & jerk lifts comprised Group A (good at snatch), while those who had a greater difference in scores comprised Group B (NOT good at snatch). The two-dimensional position coordinates of the barbell of each athlete's best snatch attempt during competition were calculated from video analysis to determine the kinematic variables of the barbell. Heel contact time was also determined from video images and compared between groups. The results supported the hypothesis: athletes in Group A had a significantly smaller mean vertical velocity of the barbell in the 1st pull phase than the athletes in Group B (0.45±0.05[m/s], 0.52±0.05[m/s], p<0.001, d=1.179). However, there were no significant differences in mean vertical velocity of the barbell in the 2nd pull phase or in vertical maximum velocity between groups. Heel contact time was also significantly larger in Group A (0.61±0.04[s], 0.53±0.06[s], p<0.001, d=1.347). Finally, there was a negative relationship between the mean vertical velocity of the barbell during the 1st pull phase of the snatch and the best snatch attempt that standardized body weight (r=-0.287, p<0.05). These results suggest that slow and careful execution of the 1st pull and keeping the feet flat in the snatch positively affect the performance.
- 著者
- 山下 大地 西牧 未央 長尾 秀行 池田 道生 沼田 幹雄 井上 謙二 西口 茂樹
- 出版者
- 独立行政法人 日本スポーツ振興センター国立スポーツ科学センター
- 雑誌
- Journal of High Performance Sport (ISSN:24347299)
- 巻号頁・発行日
- vol.6, pp.33-43, 2020
Wrestlers are categorized into a series of weight classes to ensure fair competition. Since the implementation of new rules in January 2018, weight categories and the timings of weigh-ins have changed. The purpose of the study was to establish baseline physical profiles, such as body composition, muscle strength, power, and endurance for Japanese elite freestyle wrestlers in each of the new weight classes. We collected a total of 242 data points from 70 elite Japanese male freestyle wrestlers at 14 training camps over two years. Body composition measurements, one-repetition maximum tests (bench press, parallel back squat, one-handed dumbbell snatch, and weighted chinup) and muscle endurance tests (pull-up) were performed. Body fat percentages for wrestlers in the 86-kg class or below were from 9.1% to 11.6%, whereas body fat percentages for wrestlers in the 92-, 97-, and 125-kg classes were 14.0 ± 3.5, 19.8 ± 6.9, and 26.6 ± 3.4%, respectively. This result suggests that the wrestlers in the heavier weight classes have a higher capacity to reduce body fat and increase muscle mass, which is essential if they improve strength and power. Absolute muscle strength and power performance tended to increase with heavier classes (the major results were as follows: 1RM bench press: 88.0 ± 13.0 kg in the 57-kg class and 142.0 ± 13.0 kg in the 125-kg class), whereas these relative values tended to decrease with heavier classes. Muscle endurance performance tended to decrease with heavier classes (the pull-up test: 23.8 ± 1.5 repetitions in the 61-kg class and 10.0 ± 5.4 repetitions in the 125-kg class). This study provides baseline data that can be used in the prescription of individual training programs for wrestlers, assessing areas of strength and weakness, and developing the wrestler's technical-tactical strategies.