The time course of muscle-tendon properties and function responses of a five-minute static stretching exercise     

《European Journal of Sport Science》2013,13(9):1195-1203

Abstract

The purpose of this study was to investigate the time course of the changes of muscle-tendon mechanical properties and the function responses of the plantar flexor muscles following 5?×?60?s of static stretching.

Fourteen healthy volunteers were tested on four separate days in a random order with three different rest times (0, 5, 10?min) after 5?×?60?s of stretching or following a control period without stretching. During each test, the dorsiflexion range of motion (RoM), passive resistive torque (PRT), and maximum voluntary contraction (MVC) were measured with a dynamometer. Ultrasonography of the gastrocnemius medialis (GM) muscle-tendon junction displacement and motion capture allowed us to determine the length changes in the tendon and muscle, respectively, and hence to calculate their stiffness.

We observed an increase in RoM and decrease in MVC at 0, 5, and 10?min post-stretching. This could be attributed to an increase in muscle elongation which lasted at least 10?min. A decrease in muscle-tendon stiffness was observed immediately, but not 5 or 10?min after the stretching. A decrease in PRT and muscle stiffness was observed up to 5?min after the stretching. No changes were detected in tendon stiffness or in any variable in the control group.

The effects of a 5?×?60?s static stretching exercise changes the muscle-tendon functions (RoM, MVC), which are related to mechanical changes of the muscle but not the tendon structure, respectively. Although the functional changes last for at least 10?min, changes in muscle stiffness were only observed up to 5?min after the stretching exercise.  相似文献   

Effect of a concentric warm-up exercise on eccentrically induced soreness and loss of function of the elbow flexor muscles     

Stephen A. Ingham  Ken A. van Someren  Glyn Howatson 《Journal of sports sciences》2013,31(13):1377-1382

Abstract

The aim of this study was to examine the effect of concentric warm-up exercise on eccentrically induced changes in muscle strength, range of motion, and soreness of the elbow flexors. Ten resistance-exercise naïve participants performed intermittent incremental eccentric actions (42 in total) of the elbow flexor muscles of each arm to induce muscle damage. The arms of each participant were randomly assigned either to a pre-eccentric exercise warm-up involving intermittent concentric exercise (warm-up) or no prior exercise (control). Strength, range of motion, and ratings of soreness were recorded before and 1, 2, 3, 4, and 7 days after exercise. Strength, range of motion, and soreness during muscular movements changed over time (P at most 0.01; Cohen's d at least 0.51, medium). There was an interaction (P < 0.001) for strength, showing a smaller reduction after exercise for warm-up than control (P < 0.001, d = 2.44, large effect). The decreased range of motion was less for warm-up than control for the arm while extended (P < 0.001), flexed (P = 0.002), and relaxed (P = 0.004). Muscle soreness was reduced for the warm-up group, while the muscle was flexed, extended, and relaxed compared with control (P < 0.001). The results demonstrate that a concentric warm-up exercise attenuates the reduction in loss of strength, range of motion, and muscle soreness after eccentric-exercise-induced muscle damage and might allow higher intensities of training to be performed.  相似文献   

日本自愿式环境协议实施评析及对我国环境保护管理的启示     

胡云红 《河北师范大学学报(哲学社会科学版)》2012,(2):146-152

自愿式环境协议发源于日本,并渗透到了日本民众生产、生活的方方面面。本文在回顾日本自愿式环境协议产生和发展的基础上,重点介绍其协议类型、内容和实施状况,以期为我国环境协议的实施与普及提供有益借鉴。  相似文献   

我国转基因食品标识制度的立法探讨     

王泉 《佳木斯教育学院学报》2012,(9):423+425

随着生物技术的发展,转基因食品对环境及健康潜在的风险开始为人们所认识,现阶段为转基因食品加贴特殊标识能有效保护消费者的知情权,本文在介绍了美国、欧盟、日本有关转基因食品标识立法,分析了我国有关转基因食品标识的法律规范,提出了制定专门的转基因食品标识法、制定统一的转基因产品标识国家标准、和设定转基因食品强制标识的阀值等建议。  相似文献   

国外教育志愿服务相关研究述评     

黄金结 《江西师范大学学报(哲学社会科学版)》2013,(5):43-48

国外教育志愿服务相关研究主要涉及社区教育、学生志愿服务、未成年人成长和保护、志愿服务组织等四个方面,重点探讨如何满足服务对象的需求、如何发挥志愿服务的育人功能、如何实现对志愿服务组织的有效管理等问题。相比而言,国内教育志愿服务研究存在一定的差距,亟需拓宽领域、明确重点、挖掘深度、多学科互动和对话。  相似文献   

There is no business model for open educational resources: a business model approach     

Frank de Langen 《Open Learning》2013,28(3):209-222

The economic proverb ‘There is no such thing such as a free lunch’ applies also to open educational resources (OER). In recent years, several authors have used revenue models and business models to analyse the different sources of possible funding for OER. In this article the business models of Osterwalder and Chesbrough are combined with research on the motives of the participants of OER to analyse possible funding models. If the motives of governments (knowledge economy), educational institutions (efficiency, marketing), individual producers (reputation, academic interests) and users (intermediary educational products, learning) are combined, it is shown that the only long-term sustainable independent business model is based on subsidies. However, this conclusion depends both on the definition of openness (in the sense of at no cost) and on motives. More research on both aspects could alter these conclusions.  相似文献   

民办高职院校“双师素质”教师队伍建设初探——基于重庆正大软件职业技术学院的个案研究     

谢正兰  刘亚妮 《重庆职业技术学院学报》2009,18(4):38-41

高等职业院校的师资队伍建设问题,一直是制约高职教育发展质量的瓶颈。本文从＂双师素质＂教师内涵入手,分析重庆正大软件学院＂双师素质＂队伍建设取得的成绩和存在的问题,结合＂产教结合——校企合作＂模式,从实践层面提出了构建＂双师素质＂教师队伍的途径和管理激励措施。  相似文献   

The children's centre teacher role: developing practice in the private,voluntary and independent sector     

Ros Garrick  Anne Morgan 《Early Years: An International Journal of Research and Development》2009,29(1):69-81

This study assessed the impact of the role of the teacher in two children's centres in England and identified some of the supporting and limiting factors that influenced outcomes. The teachers worked across several settings in the private, voluntary and independent (PVI) sector, with the aim of enhancing early years practice and practitioner confidence. A conceptual framework was devised to model the impact of the teacher role based on Leithwood and Levin (2005 Leithwood K, Levin B. 2005. Assessing school leader and leadership programme effects on pupil learning. DfES Research Report 662. http://www.dfes.gov.uk/research/data/uploadfiles/RR662.pdf (accessed December 2006) [Google Scholar]). Teachers were found to bring vital professional knowledge and experience to the role and delivered their methods through a range of leadership styles as identified in the literature. Teachers were successful in developing practice and staff confidence in settings; this also impacted positively on outcomes for children. However, success was dependent on a number of moderating factors, including sector‐related factors such as the qualifications of staff. Implications for policy and practice are discussed.  相似文献   

我国企业内部控制执行机制系统构建研究     

晓芳 《未来与发展》2012,35(9):87-90

完备的内部控制制度体系的建立只是完善企业内部控制的初步目标,必须要有有效的执行机制才能达到预期的效果.结合我国的制度背景,本文在对我国企业内部控制执行机制现状进行分析与评价后,提出了我国现阶段在企业内部控制执行上应采取以强制执行机制为基础和保障,逐步强化自我执行机制的思路,并提出了相应的对策建议.  相似文献   

Innovation intermediaries and collaboration: Knowledge–based practices and internal value creation     

Muthu De Silva  Jeremy Howells  Martin Meyer 《Research Policy》2018,47(1):70-87

This paper analyses how knowledge-based practices adopted by innovation intermediaries enable them to generate value for themselves when collaborating with their clients. While the literature focuses on value creation for their client organisations, little is known about how innovation intermediaries create internal value even though this is essential for ensuring their long-term survival and sustaining their key facilitating role in the innovation system. This understudied issue is explored using empirical evidence from a sub-set of innovation intermediaries, Research and Technology Organisations (RTOs). The results indicate that by capitalising on existing knowledge vested in employees and collaborators as well as understanding and shaping the knowledge base of the innovation ecosystem, innovation intermediaries generate internal value from their involvement in collaborative innovation, which range from different financial to non-financial types of value. Implications for intermediaries, their collaborators and for policymakers are then discussed.  相似文献