等动测力及康复训练系统在运动员膝关节损伤后力量训练中的应用

研究利用等动测力及康复系统对膝关节损伤的女运动员进行等速向心训练。经过约8周的训练,患膝屈伸肌群的峰值力矩在不同测试速度下均有显著提高,但伸肌峰值力矩提高较屈肌快。此次研究表明等速向心训练对膝关节损伤后的肌肉功能恢复有一定的促进作用。     

踢毽对中老年人下肢肌肉力量和伸展的影响

采用CybexⅡ^ 等速肌力测试系统对持续踢毽锻炼2年的广州市128名中老年人的膝关节屈、伸肌群力量进行标准化、定量化测量，结果表明：男、女屈、伸膝肌群耐力(ER)、爆发力(TAE)自身前后对照各项肌力指标均有显著性差异。     

运动性低血色素大鼠骨骼肌自由基代谢的变化的研究

运动性低血色素是影响运动能力的重要因素之一,但处于运动性低血色素状态时骨骼肌自由基代谢变化规律目前研究较少,本实验通过11周递增负荷跑台运动建立大鼠运动性低血色素模型,并对大鼠骨骼肌自由基代谢的变化进行研究,了解运动性低血色素大鼠骨骼肌自由基代谢变化的规律.实验结果表明:1、递增负荷跑台训练导致运动性低血色素大鼠骨骼肌中抗氧化酶活性明显降低,是造成自由基代谢紊乱的重要因素;2、运动性低血色素大鼠Hb水平下降与骨骼肌SOD水平下降具有相关性.     

骨骼肌损伤的机制

用电镜和免疫电镜观察超过习惯负荷后人骨骼肌收缩结构和收缩蛋白定位延迟性变化的结果提示：超过习惯负荷后延迟发生的骨骼肌收缩蛋白的降解优势导致收缩结构的改变或解体。这种收缩结构的改变构成了后继负荷工作的背景，如后继负荷能促进收缩蛋白的合成则可促进收缩结构的恢复和增强；如后继负荷导致收缩蛋白降解优势的积累和稳定，则将引起收缩结构变化的积累和稳定而导致骨骼肌的慢性或急性损伤。这种变化的一过性和两向发展的可能性提示：在未形成稳定的变化之前，其变化性质是生理的或是生理—病理双向变化的过渡的性质。骨骼损伤的预防主要在于是否根据承受能力的可能性而适当地安排工作负荷     

核心力量训练的基本问题——核心区与核心稳定性

探讨核心区与核心稳定性两个最基本且仍存争议的问题。结果表明:(1)核心是"腰椎—骨盆—髋关节"形成的一个整体,是人体的中间环节,具体指膈肌以下盆底肌以上的中间区域,含有41对+1块肌肉群;大核心指肩关节以下髋关节以上,包括骨盆、胸廓和整个脊柱在内的区域,有55对+1块肌肉群。(2)提出核心稳定性系统结构模型,认为核心稳定性训练主要有稳定姿势和重心、发力减力、导力和预防损伤等作用。(3)提示:在稳定性基础上发展快速力量;注重运用一般力量来发展专项力量;核心力量训练是传统力量训练的有益补充,两者并无优劣之分,应根据实际需要来选择适宜的训练内容和方法。     

Differences in hamstring activation characteristics between the acceleration and maximum-speed phases of sprinting

This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances.     

Effects of inspiratory muscle training in professional women football players: a randomized sham-controlled trial

This study was conducted to determine the effects of inspiratory muscle training (IMT) on respiratory and peripheral muscles oxygenation during a maximal exercise tolerance test and on repeated-sprint ability (RSA) performance in professional women football players. Eighteen athletes were randomly assigned to one of the following groups: SHAM (n = 8) or IMT (n = 10). After a maximal incremental exercise test, all participants performed (on a different day) a time-to-exhaustion (Tlim) test. Peripheral and respiratory muscles oxygenation by near-infrared spectroscopy, breath-by-breath ventilatory and metabolic variables, and blood lactate concentration were measured. The RSA test was performed on a grass field. After a 6 week intervention, all athletes were reevaluated. Both groups showed increases in inspiratory muscles strength, exercise tolerance and RSA performance, however only the IMT group presented lower deoxyhemoglobin and total hemoglobin blood concentrations on intercostal muscles concomitantly to an increased oxyhemoglobin and total hemoglobin blood concentrations on vastus lateralis muscle during Tlim. In conclusion, these results may indicate the potential role of IMT to attenuate inspiratory muscles metaboreflex and consequently improve oxygen and blood supply to limb muscles during high-intensity exercise, with a potential impact on inspiratory muscle strength, exercise tolerance and sprints performance in professional women football players.     

运动对心肌、骨骼肌HSP70表达影响的研究进展

热休克蛋白的分子伴侣、抗氧化、抗损伤、协同免疫及抗细胞凋亡等多种功能,不仅生物界对它越来越关注,而且运动医学界的学者也对它产生了浓厚的兴趣。HSP70作为细胞应激蛋白,对不同强度与形式的运动,其反应和适应有很大差异,这为我们进一步认识运动规律,从而进行科学的体育锻炼和运动训练提供了新的思路和方法。     

Bilateral deficit in power production during multi-joint leg extensions

Abstract

The purpose of this study was to determine the presence of the bilateral deficit both as a function of overall and individual joint power. Most studies addressing the deficit have assessed force; however, in most sporting events maximal power is more important than maximal force production. To address this, in the current study we assessed the bilateral deficit for multi-joint movements as measured by overall lower extremity and individual joint power. We assessed power production using an isokinetic machine permitting both unilateral and bilateral leg extensions. Several significant effects and interactions between the contraction type (unilateral, bilateral, alternating unilateral), side of the body, lower extremity joint, and percentage of a 1-RM load were revealed. All interactions were between the lower extremity joints (hip, knee, ankle) and involved the contraction protocol (P=0.001), the percentage of 1-RM load (P=0.0002), and the side of the body (P=0.0003). Taken together, the results indicate that the bilateral deficit is manifested using a measure of power, but more importantly, the deficit has differential implications based on the overall resistance, and various joints involved in the movement. In conclusion, a reduction in power generation was evidenced for both simultaneous contractions of the leg extensors as well as reciprocal contractions. With reduced contributions from the knee joint during bilateral and reciprocal contractions, combined with past research demonstrating differential activation of mono-articular knee joint muscles, evidence for reduced contributions from the peripheral nervous system are suggested based on the results of this study.     

封闭加热敷治疗腘绳肌损伤初探

腘绳肌损伤是体育运动中的一种多发运动损伤。试用封闭加热敷的方法对１４ 例腘绳肌损伤患者进行治疗, 并对腘绳肌损伤机理及治疗依据进行分析