- 著者
- 吉本 隆哉 千葉 佳裕 為末 大 大沼 勇人 谷中 拓哉 松林 武生 杉崎 範英 礒 繁雄 山崎 一彦
- 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.65, pp.495-505, 2020 (Released:2020-08-26)
- 参考文献数
- 33
This study was designed to clarify the relationships between the muscle cross-sectional area of the trunk and thigh and 400-m hurdle time in 12 young adult male athletes include a bronze medalist in the world championships (height 175.4 ± 6.0 cm, body mass 67.9 ± 5.8 kg, 400-m hurdle time 47.89―55.41 s). Crosssectional images from the origin to insertion of the trunk and thigh muscles were obtained using magnetic resonance imaging (MRI). These images were used to calculate the absolute cross-sectional areas of each muscle as indices of muscularity. Stepwise multiple regression analysis was performed to examine the association between the indices and 400-m hurdle time. This analysis produced an equation (adjusted R2 = .868) with the semitendinosus (β = −0.611, P = .001), quadratus lumborum (β = −0.300, P = .044) and adductor brevis (β = −0.395, P = .014) as the explanatory variables. It was concluded that individual differences in 400-m hurdle performance can be explained by the semitendinosus, quadratus lumborum and adductor brevis.
2 0 0 0 OA 腱スティフネス,筋力および筋活動が反動動作による機械的仕事量増強の個人差に与える影響
- 著者
- 平山 邦明 杉崎 範英 加藤 えみか 金久 博昭 福永 哲夫 川上 泰雄
- 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.33-43, 2010 (Released:2010-07-20)
- 参考文献数
- 20
- 被引用文献数
- 1 1
The purpose of the present study was to examine the influence of tendon elasticity, muscle strength and muscle activities on the amount of mechanical work enhancement associated with a counter movement. Twenty-one athletes performed a unilateral maximal jump using only the ankle joint with (CMJ) and without (no-CMJ) a counter movement on a sledge apparatus. Mechanical work done by the ankle joint was calculated from the ground reaction force and ankle joint kinematic parameters, and the difference between CMJ and no-CMJ conditions (ΔWork) was determined. During the exercise, electromyographic (EMG) activities were recorded from the triceps surae muscles. The maximal isometric plantar flexion torque and Achilles tendon stiffness were also determined using a torque meter and ultrasonogram. No significant correlation was found between ΔWork and either tendon stiffness or the maximal torque. In addition, neither the difference between CMJ and no-CMJ in iEMG nor mEMG was correlated with ΔWork. On the other hand, ΔWork was significantly correlated with the integrated EMG during the braking phase (r=0.52, p<0.05) and both the integrated (r=0.55, p<0.01) and mean (r=0.53, p<0.05) EMG during the push-off phase of CMJ. These results suggest that individual differences in ΔWork are influenced not by differences in the mechanical properties of the muscle-tendon unit, but by the individuality of muscle activities during CMJ.