大白鼠腓肠肌—骨标本被动拉伸时弹性刚度测定

骨骼肌是构成人体运动器系的重要生物材料,它以具有高度可兴奋性而使其性质非常复杂。为研究骨骼肌在被动拉伸时的力学性能,本文拟通过对大白鼠腓肠肌—骨标本被动拉伸时的力量—时间曲线的分析,计算骨骼肌在两种拉伸速度下兴奋与松驰状态的弹性刚度,尝试着解释骨骼肌的弹性刚度与结构之间的关系,以便为肌肉力学的研究提供一些参考。 以20只Wistar雄性大白鼠为实验对象,麻醉后制成腓肠肌—骨标本进行快速拉伸实验,实验机可提供0.     

适应性训练对骨骼肌肌力、骨架蛋白含量的影响

以雄性Wistar大鼠为研究对象,进行"3周、6周适应性离心运动训练"两种方式运动.其中3周适应性离心训练(渐进增加强度),每周5天训练,速度从20.0 m/min增加到32.5 m/min,每次20 min,-5°下坡间歇跑.6周适应性离心训练(相同强度),每周5天训练,前3周速度从20.0 m/min增加到32.5 m/min,后3周保持35.0 m/min,每次20 min,-5°下坡间歇跑.离心运动后不同时段和适应性训练后取大鼠后肢腓肠肌外侧头进行分析.6周适应性训练组进行一次性大强度离心运动,一次性离心运动实验为-16°下坡跑台跑,定量大负荷间歇性运动,跑速为26.8 m/min,运动5 min×10组,组间歇1 min.研究适应性训练后大鼠腓肠肌收缩力和拉断力和骨骼肌细胞骨架蛋白含量的变化特点;分析肌收缩力和拉断力与肌细胞骨架蛋白缺失的关系以及与延迟性骨骼肌损伤时血清酶升高的关系;通过观察大鼠经过适应性训练后,骨骼肌肌力及肌细胞基质蛋白含量是否会有适应性的变化,是否会因此提高对抗大强度离心运动所致骨骼肌损伤的能力.     

肌肉的质和力量的关系

一般来说,肌肉本身力量和它的横断面成正比。的确,肌肉的横断面和它的潜在最大收缩力有着密切的关系。每平方厘米骨骼肌横断而能产生4——6公斤的张力。肌肉越大,力量越大。但有一点容易产生误会的,就是往往以整个臂围,作为衡量肌肉大小的尺度,其实有时     

德国的力量训练研究

力量是各项素质的基础,是取得优异成绩的关键,因此德国训练学界对力量训练研究给予高度重视。他们不仅建立了国家级的力量专门研究机构——“联邦力量研究所”,而且先后涌现出一批诸如比勒、莱奈尔茨、施密特布莱希尔和高豪夫等以力量训练为主要研究领域的世界级著名学者。他们十分重视理论与实践的相互结合,注重研究成果的实际运用价值。 例如:施密特布莱希尔用“力—时间—曲线”的关系即“冲量”来描述和评价速度力量。他认为速度力量的优劣水平取决于力值的上升速度、由此达到的最大力值和力的作用时间。比勒提出“启动力”是速…     

慢性力竭性训练对大鼠骨骼肌细胞凋亡的影响

为了研究力竭性训练对大鼠骨骼肌细胞凋亡的影响，对大鼠进行为期８周的力 竭性游泳训练，用ＤＮＡ原位末端标记法检测骨骼肌细胞的凋亡，并用免疫组化的方 法检测骨骼肌细胞中ｂｃｌ—２和Ｆａｓ蛋白的表达情况。结果发现：①力竭性训练后，大 鼠骨骼肌细胞凋亡显著增加。骨骼肌细胞凋亡可能是力竭性训练导致肌肉酸痛和运动 能力降低的病理生理机制。②力竭性训练后，大鼠骨骼肌细胞中ｂｃｌ—２蛋白的表达显 著下降，Ｆａｓ蛋白的表达轻度增加。因此，力竭性训练可抑制骨骼肌细胞ｂｃｌ─２蛋白 的表达而促进Ｆａｓ蛋白的表达，这可能是力竭性训练导致大鼠骨骼肌细胞细胞凋亡发 生的基因调控机制。③力竭性训练后，大鼠骨骼肌组织和血清中ＳＯＤ活性显著下降， ＭＤＡ含量显著增加。因此，力竭性训练使机体抗氧化能力下降，导致氧自由基生成 增多，这可能也是骨骼肌细胞凋亡的调节机制。     

胰岛素样生长因子- I 对骨骼肌生长和修复研究进展

生长激素（GH）／胰岛素样生长因子-I（IGF-I）轴是肌肉生长的重要调节因子之一。虽然许多组织都能表达IGF-I，但它们各自的功能不同。骨骼肌是IGF—I的靶器官，同时也分泌IGF—I。骨骼肌组织表达的IGF—I对骨骼肌损伤后的再生、修复非常重要，也是通过适当干预保持肌肉质量的重要调节因素。主要讨论GH／IGF—I在促进骨骼肌再生和修复中的作用，并讨论其在运动康复中的应用前景。     

《体育教学与科研》一九八六年总目录索引

人体运动参数摄影、肌电、力的同步测定 张家正(86.1)运动生物力学的教学与研究应适应时代要求 李树屏(56一)人体环节参数(美)稍1 lia‘5 Lissner(。6.1)增大跑速对着地时小腿峰值制动的影响 (美)T .E.Clarke等(se.2)链球投掷过程中影响速度波动的因素 (美)J .Dapena(56.2)用超声波技术定量研究负重足足拱 (美)E.M.亥尼格(86.2)正足背射门偏高的生物力学诊断 张贻琪(56.5)由乒乓球旋转起因所想到的许方(86.3)骨骼肌被动拉伸时力学性质研究侯曼(863)调整J恩维逻辑,增强开拓能力—运动生物力学的研究现状与发展趋势 刘世藩(56.4)肌电图生…     

运动抗衰老:端粒机制的研究进展

为进一步了解运动与端粒长度之间的关系,综述端粒长度与衰老的关系、运动对端粒长度的影响以及运动影响端粒长度的潜在作用机制3个方面。结论:1)端粒长度缩短会使DNA损伤导致细胞产生非功能蛋白进而引起凋亡衰老;2)运动与端粒长度之间存在一定关联:正相关和倒U型关系,并且可能与具体的运动处方有关;3)运动对端粒长度的有益影响可能是通过端粒酶活性的增加、氧化应激减轻、炎症减轻和骨骼肌的TERRA上调等条件来介导,同时还有miRNAs的调控及端粒相关蛋白的作用,但其中更为具体的作用机制仍有待进一步探究。     

谈提高短跑协调放松能力

协调放松能力是指运动员在高速奔跑中,神经系统和运动系统协调配合,使肌肉收缩与放松能按照短跑技术动作的工作性质协调进行,从而增加跑的步频与步长。它能增加肌肉收缩前的肌纤维长度,特别是放松对抗肌群,有助于提高肌肉收缩速度,增加肌涨力,增大步长。     

跳远助跑速度利用率模型的提出及验证

通过对支持高助跑速度利用率与支持低助跑速度利用率双方论据的整理与分析,发现目前我国不管是要求跳远运动员维持高助跑速度利用率的论点,还是强调降低助跑速度利用率的论点,都不能准确地描述助跑速度利用率与跳远成绩的本质关系.结合双方争论的观点与论据提出跳远助跑速度利用率—成绩曲线的模型,用于解释及反映助跑速度利用率与跳远成绩间的本质关系.     

Changes in force production, blood lactate and EMG activity in the 400-m sprint.

The neural activation (iEMG) and selected stride characteristics of six male sprinters were studied for 100-, 200-, 300- and 400-m experimental sprints, which were run according to the velocity in the 400 m. Blood lactate (BLa) was analysed and drop jumps were performed with EMG registration at rest and after each sprint. Running velocity (P less than 0.001) and stride length (P less than 0.05) decreased and contact time increased (P less than 0.01) during the 400-m sprint. The increase in contact time was greatest immediately after runs of 100 and 300 m. The peak BLa increased and the rate of BLa accumulation decreased with running distance (P less than 0.001). The height of rise of the centre of mass in the drop jumps was smaller immediately after the 300 m (P less than 0.05) and the 400 m (P less than 0.01) than at rest, and it correlated negatively with peak BLa (r = -0.77, P less than 0.001). The EMG and EMG:running velocity ratio increased with running distance. It was concluded that force generation of the leg muscles had already begun to decrease during the first quarter of the 400-m sprint. The deteriorating force production was compensated for until about 200-300 m. Thereafter, it was impossible to compensate for fatigue and the speed of running dropped. According to this study, fatigue in the 400-m sprint among trained athletes is mainly due to processes within skeletal muscle rather than the central nervous system.     

Does inside passing contribute to the high incidence of groin injuries in soccer? A biomechanical analysis

Groin injuries are common in soccer and often cause time-loss from training. While groin injuries have been linked to full effort kicking, the role of inside passing is unclear. Therefore, the purpose of this study was to investigate hip joint kinematics and muscle force, stress and contraction velocity for adductor longus and gracilis during inside passing. 3D kinematics of ten soccer players (23.4 yrs; 77.5 kg; 1.81 m) were captured with a motion capture system inside a Footbonaut. Muscle force and contraction velocity were determined with AnyBody Modelling System. Gracilis muscle forces were 9% lower compared to adductor longus (p = 0.005), but muscle stress was 183% higher in gracilis (p = 0.005). Contraction velocity reveals eccentric contraction of gracilis in the last quarter of the swing phase. Considering the combination of eccentric contraction, high muscle stress and the repetitive nature of inside passing, gracilis accumulates high loads in matches and training. These results indicate that the high incidence of groin injuries in soccer could be linked to isolated pass training. Practitioners need to be aware of the risk and refrain from sudden increases in the amount of pass training. This gives the musculoskeletal system time to adapt and might avoid career threatening injuries.     

锌与睾酮对力竭性游泳大鼠骨骼肌的影响

动态观察了缺锌和缺锌后补锌以及补充睾酮对大鼠力竭性游泳前后骨骼肌的影响。结果显示,缺锌引起大鼠体重、体长、尾长、趾长伸肌重量、肌四头肌深层肌总RNA含量的明显降低。缺锌影响骨骼肌的代谢速率,阻碍力竭性游泳后骨骼肌总蛋白和总RNA含量的升高,并引起骨骼肌F肌动蛋白的下降,G-肌动蛋白的异常升高。补充睾酮,对缺锌造成的影响无改善作用。缺锌大鼠经过补锌,上述各项指标能恢复或基本恢复。实验还表明,缺锌可影响运动后骨骼肌的恢复。锌缺乏时骨骼肌合成代谢受阻,与睾酮的减少没有关系。     

肌肉力量连续统一体理论及其在力量训练中的应用研究

通过对肌肉力量中主动张力和被动张力的关系所作的深入探讨,认为肌肉在不同收缩形式和收缩速度下,肌力的组成以及各组成成分之间既相互区别又相互联系,形成一个连续统一体。这为力量训练理论与实践研究开辟了新的思路。     

男子跳高一二级运动员髋关节肌力特征对比研究

采用等速测力实验等研究方法，对男子跳高一二级运动员髋关节肌力进行测试分析。发现两者表现出以下肌力平衡特征：一级运动员髋关节的肌力特征与跳高起跳技术用力特点相一致，即摆动腿髋关节屈肌力显著大于起跳腿，屈肌缺失值和伸肌缺失值较大；摆动腿髋关节屈伸比大、起跳腿小。而二级运动员髋关节肌力矩未表现出此特征。     

Muscle - tendon unit mechanical and morphological properties and sprint performance

The objective of this study was to determine whether sprint performance is related to the mechanical (elongation - force relationship of the tendon and aponeurosis, muscle strength) and morphological (fascicle length, pennation angle, muscle thickness) properties of the quadriceps femoris and triceps surae muscle - tendon units. Two groups of sprinters (slow, n = 11; fast, n = 17) performed maximal isometric knee extension and plantar flexion contractions on a dynamometer at 11 different muscle - tendon unit lengths. Elongation of the tendon and aponeurosis of the gastrocnemius medialis and the vastus lateralis was measured using ultrasonography. We observed no significant differences in maximal joint moments at the ankle and knee joints or morphological properties of the gastrocnemius medialis and vastus lateralis between groups (P > 0.05). The fast group exhibited greater elongation of the vastus lateralis tendon and aponeurosis at a given tendon force, and greater maximal elongation of the vastus lateralis tendon and aponeurosis during maximum voluntary contraction (P < 0.05). Furthermore, maximal elongation of the vastus lateralis tendon and aponeurosis showed a significant correlation with 100-m sprint times (r = -0.567, P = 0.003). For the elongation - force relationship at the gastrocnemius medialis tendon and aponeurosis, the two groups recorded similar values. It is suggested that the greater elongation of the vastus lateralis tendon and aponeurosis of the fast group benefits energy storage and return as well as the shortening velocity of the muscle - tendon unit.     

The effects of skiing velocity on mechanical aspects of diagonal cross-country skiing

Cycle and force characteristics were examined in 11 elite male cross-country skiers using the diagonal stride technique while skiing uphill (7.5°) on snow at moderate (3.5 ± 0.3 m/s), high (4.5 ± 0.4 m/s), and maximal (5.6 ± 0.6 m/s) velocities. Video analysis (50 Hz) was combined with plantar (leg) force (100 Hz), pole force (1,500 Hz), and photocell measurements. Both cycle rate and cycle length increased from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal compared to high velocity. The kick time decreased 26% from moderate to maximal velocity, reaching 0.14 s at maximal. The relative kick and gliding times were only altered at maximal velocity, where these were longer and shorter, respectively. The rate of force development increased with higher velocity. At maximal velocity, sprint-specialists were 14% faster than distance-specialists due to greater cycle rate, peak leg force, and rate of leg force development. In conclusion, large peak leg forces were applied rapidly across all velocities and the shorter relative gliding and longer relative kick phases at maximal velocity allow maintenance of kick duration for force generation. These results emphasise the importance of rapid leg force generation in diagonal skiing.     

从运动生理学的角度探析“翻龙泉”活动的民族传统体育属性

从运动生理学的角度,通过综合比较分析学生参加＂翻龙泉＂活动训练前后身体成分的变化,来进一步确认该项目具有增进体质健康的体育的本质属性。结果表明：＂翻龙泉＂活动对学生的身体形态、骨骼肌量（SMM）、身体脂肪（BF）、基础代谢率（BMR）等各项指标在训练前后相比具有显著性差异（p〈0.05）,参加该活动训练能改善学生身体形态,促进骨骼肌生长,有效减少体脂肪和肥胖程度,使身体质量指数（BMI）更趋合理,能提高学生的基础代谢率和健康评估水平,因而从运动生理学方面确认了＂翻龙泉＂活动的民族传统体育属性。