Reproducibility of an isokinetic eccentric muscle endurance task

Abstract

Despite the widespread use of isokinetic eccentric muscle endurance protocols, no research has examined the absolute and relative reliability of such tests. The aim of this study was to examine the reliability of an isokinetic eccentric knee muscle endurance task. Fifteen healthy untrained males volunteered to take part in the study and written informed consent was obtained. The procedures received approval from the University Research Ethics Committee. Participants visited the laboratory on three separate occasions: 2 weeks before testing to familiarize them with the experimental procedures, and on two separate occasions, 2 weeks apart and at the same time of day. Isokinetic eccentric knee extension and flexion movements of the dominant limb were performed using a calibrated dynamometer (Biodex System 3). Range of motion during testing was set using voluntary maximal full extension (0 rad) to 1.57 rad of knee flexion and testing was conducted at 1.56 rad · s^?1. Participants performed four maximal efforts to determine maximal peak torque. After 2 min rest, participants completed the all-out endurance test of 50 continuous eccentric repetitions. Data were gravity corrected and windowed to only include constant velocity periods. Repeated-measures analyses of variance were used to examine differences in maximal peak extension and flexion torque and the maximal torque measurement recorded during the endurance test. Absolute and relative reliability of the torque fatigue index, work fatigue index, and total work were assessed through calculation of intra-class correlation coefficients, coefficients of variation, and absolute 95% limits of agreement using the methods described by Bland and Altman (1986). Differences between the strength test and the endurance trial for peak torque were found to be non-significant for both quadriceps (323 vs. 323 N · m) and hamstrings (183 vs. 178 N · m). The intra-class correlation coefficients revealed significant (P<0.05) positive moderate to strong correlations (r=0.44–0.94) across repeated trials for all parameters except hamstring torque fatigue (P=0.11) and hamstring work fatigue index (P=0.08). Coefficients of variation ranged from 6% to 48% and were large for the work fatigue index and torque fatigue index but acceptable for total work for both the extensors and flexors. The 95% limits of agreement indicated systematic bias in repeated trials for both the work fatigue index and torque fatigue index for extensors and flexors, ranging from ?3% to ?10%, with less fatigue evident in the second test. There was also systematic bias for total work, with more work being performed during the second than the first test for both extensors and flexors. The random error was large for all variables and there was greater random error in the hamstrings compared with the quadriceps. Together with moderate to strong intra-class correlation coefficients and large coefficients of variation, the data suggest that there is small systematic bias in repeated eccentric muscle actions for both the quadriceps and hamstrings, although the random error was large despite habituation procedures. Therefore, data from an isokinetic eccentric muscle endurance task should be viewed with some caution even when participants receive considerable habituation before assessment.     

Tool for Assessing Responsibility-Based Education (TARE): Instrument Development,Content Validity,and Inter-Rater Reliability

Numerous scholars have stressed the importance of personal and social responsibility in physical activity settings; however, there is a lack of instrumentation to study the implementation of responsibility-based teaching strategies. The development, content validity, and initial inter-rater reliability testing of the Tool for Assessing Responsibility-Based Education (TARE) are described here. Inter-rater agreement was calculated for paired observations focused on 2 different teachers delivering a total of 18 separate physical education lessons for students in grades 1 through 6. Findings indicate that the Tool for Assessing Responsibility-Based Education provides scores with adequate inter-rater reliability. The procedures employed in this study proved feasible and enable observers to characterize the implementation of responsibility-based teaching in physical education. The Tool for Assessing Responsibility-Based Education has numerous research and training applications relative to the Teaching Personal and Social Responsibility model (Hellison, 2003 Hellison, D. 2003. Teaching responsibility through physical activity, 2nd, 15–38. Champaign, IL: Human Kinetics.  [Google Scholar]) and the national content standards for K–12 physical education, specifically Standard 5: Exhibits responsible personal and social behavior that respects self and others in physical activity settings (National Association for Sport and Physical Education, 2004 National Association for Sport and Physical Education (NASPE). 2004. Moving into the future. National standards for physical education, 2nd, 39–43. Reston, VA: Author.  [Google Scholar]).     

A linguistic dissociation in Williams syndrome: Good at gender agreement but poor at lexical retrieval

Williams syndrome (WS) is a rareneuro-developmental disorder characterised byspared language in the face of serious deficitsin nonlinguistic cognitive abilities. Weconducted a study on ten WS individuals inwhich gender agreement and gender assignmentwere assessed by means of two tasks: gendercategorisation and gender concord. Subjectsperformed gender categorisation to real nounswhose gender was regular or exceptional giventheir ending, and to invented nouns which werecomposed of nonword or word stems and realword-endings. The same material was used in thegender concord task in which subjects had tomatch the items with the appropriate form ofthe article and the adjective carrying genderagreement. In the gender categorisation of realwords, WS were lower than controls but bothgroups demonstrated a similar sensitivity togender-ending regularities. In the gendercategorisation of nonwords, the results showeda clear dissociation. The WS subjects producedmore ending-consistent responses than thecontrols. Contrary to the controls, WS reliedheavily on the gender clue provided by theending even when the gender of the word evokedby the stem of the invented word was opposed tothat evoked by the ending. Participants with WSwere not influenced by the specific word evokedby the stem of the invented word. In the secondtask (concord task), the WS subjects performed well although lower than thecontrols. We concluded that the WS people werenot impaired in gender agreement which relieson syntactic rules and/or on the extraction ofregularities but experienced difficulties inretrieving lexical instances.     

数字资源整合检索协议研究

简要地论述了数字资源整合检索的必要性、模式、以及联接方式和联接方法，并详细地介绍了三种数字资源整合检索的协议：Z39．50、OAI、OpenuRL。     

浅谈关于仲裁协议效力的几个问题

仲裁协议是仲裁的基石。仲裁协议效力是仲裁法律制度中的重要内容。本文根据我国仲裁法的规定，结合仲裁实践中关于仲裁协议效力易发生的争议，对于仲裁协议的形式、无效仲裁协议、有瑕疵的仲裁协议效力的认定、仲裁协议效力异议的提出等问题进行了探讨和分析。     

数据加密中的密钥管理和协商技术

在介绍了XML的岳全特性和其加密规范后，从Dfffie-Heliman密钥协商的生成原理出发，运用XML加密规范所提供的对数据对象进行密钥协商的机制，并以经典的D—H密钥协商为例，依据规范所制定的原则，运用JCE所具有的安全特性为实现技术，就如何时密钥协商交换进行了探讨，从而为XML加密规范的实际应用探索了一种方式，并以此说明建立自主加密扩展的重要意义。     

论农村分担赡养老人协议的合法性

农村养老模式主要集中在三种模式,其中分担赡养老人模式问题颇多。主要从其存在的原因和法律特征和法律效力进行分析,认为这种协议应该属于一部分有效、一部分无效的协议。     

基于SNMP协议的内联网用户监视系统模型

随着企业内联网的逐步成熟,其安全性变得越来越重要。提出了基于SNMP协议的用户监视系统模型,该系统采用Web/Java技术的3层应用模型,通过SNMP协议来采集交换机中的数据信息,并与用户认证系统、DHCP服务器的日志信息进行关联分析,从而实现内联网内用户的监视过程。     

Techniques for Tracking Perpetual Access

Tracking perpetual access entitlements is a challenging task that is too often simply ignored. Here, the presenter makes the case for the importance of systematically tracking perpetual access and outlines the information that is necessary to record. The presenter also draws on the literature and conversations with ten librarians working on the issue to provide a set of techniques for this task. These techniques incorporate several different systems common to academic libraries and include scenarios that illustrate the use in common situations.     

英语主谓一致的辩证应用

以汉语为母语的英语学习者面临的难点主要体现在英语和汉语表达不同的地方,英语主谓一致即是汉语没有的重要语法现象之一。要成功掌握英语主谓一致,不仅需要牢记其规则,更需宏观理解其辩证应用含义。