Comparative Resistance Exercise Effects on Knee Osteoarthritis Pain, Functional I

描述（由申请人提供）：4000万美国人患有骨关节炎（OA），其中高达30%的人患有严重的疼痛和残疾。股四头肌肌力下降和软骨破裂与OA相关的功能损害有关。既能提高肌肉力量又能减少软骨损失的干预措施对于预防昂贵的、痛苦的慢性残疾的发生是很重要的。阻力运动已被证明可以改善症状性膝关节炎患者的身体能力和下肢疼痛；然而，早期的证据充满了主要的方法局限性。最近，令人信服的证据表明，与集中集中的阻力运动（CRX）相比，偏心集中的阻力运动（ERX）可以在更低的心血管和代谢成本下诱导肌肉质量和腿部功能的显著增加。目前还没有发表的研究比较纯ERX和CRX对OA疼痛、软骨转换和身体功能的影响。使用一种创新的阻力运动设备原型，我们的实验室将严格比较两种模式的阻力运动对症状性膝关节炎老年人这些变量的影响。本研究是一项随机、单盲对照研究，研究两种阻力运动方案对老年膝关节OA患者膝关节疼痛、身体功能和软骨转换的相对疗效。本研究的主要目的是确定四个月的ERX是否比CRX或标准治疗（非运动控制；CON）更能减轻老年人oa相关的膝关节疼痛。主要结果将是建立、可靠和有效的西安大略省和麦克马斯特大学骨关节炎指数（WOMAC评分）的膝关节疼痛亚量表从基线到第四个月的变化。次要目标1将是在第四个月确定ERX是否比CRX和CON更能改善身体功能和习惯性身体活动。通过一系列测试（分级最大步行测试、6分钟步行测试、爬楼梯测试、7天计步器测试）评估功能和习惯性体力活动。次要目标2将是在第四个月确定ERX是否会比CRX或CON诱导更大的软骨生物标志物转换变化。软骨更新将使用软骨形成（II型前胶原C-前肽，[CPII]）与软骨破坏（II型胶原C-末端肽[CTX-II]）的比率来评估。本研究将招募患有胫股膝关节炎的老年人（N=90； bbb60岁）。参与者将被随机分配到三个研究组中，每组30人。这三组将包括一个非运动控制组（CON），一个集中的阻力训练组（CRX；一组/运动，两次/周）和一个离心集中的阻力训练组（ERX；一组/运动，两次/周）。将在基线和第四个月收集研究测量数据。协方差的混合模型分析将应用于主要目标和次要目标1的结果变量。协方差分析将应用于软骨周转率的变化；Pearson相关性校正和Bonferroni校正，将被用于发现训练引起的疼痛变化、身体功能和软骨转换之间的关联。这项新研究的结果将用于进一步开发治疗膝关节OA的最佳强化处方，并防止持续的软骨破坏。

DESCRIPTION (provided by applicant): Osteoarthritis (OA) is present in 40 million Americans and up to 30% of these people experience significant pain and disability. Quadricep muscle strength decline and cartilage breakdown are associated with OA related-functional impairment. Interventions that can both improve muscle strength and minimize cartilage loss would be important for preventing onset of costly, painful chronic disability. Resistance exercise has been shown to improve physical abilities and lower knee pain in patients with symptomatic knee OA; however, earlier evidence is fraught with major methodological limitations. Recent, compelling evidence suggests that eccentrically focused resistance exercise (ERX) may induce superior increases in muscle mass and leg function at a lower cardiovascular and metabolic cost compared to concentrically focused resistance exercise (CRX). Currently, there are no published studies comparing pure ERX and CRX on OA pain, cartilage turnover and physical function. Using an innovative prototype of resistance exercise equipment, our laboratory will rigorously compare two modes of resistance exercise on these variables in older adults with symptomatic knee OA. This proposed study is a randomized, single-blind controlled study of the relative efficacy of two resistance exercise protocols on knee pain, physical function and cartilage turnover in older adults with knee OA. The Primary Aim of this study is to determine if four months of ERX will reduce OA-related knee pain in older adults more than CRX or standard care (non-exercise control; CON). The primary outcome will be the change in knee pain subscale of the well-established, reliable and validated Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC Score) from baseline to month four. The Secondary Aim 1 will be to determine if ERX improves physical function and habitual physical activity more than CRX and CON by month four. Function and habitual physical activity will be assessed by a battery of tests (graded maximal walk test, six-minute walk test, stair climbing, 7-day pedometer test). Secondary Aim 2 will be to determine whether ERX will induce greater changes in cartilage biomarker turnover than CRX or CON by month four. Cartilage turnover will be assessed using a ratio of cartilage formation (C-propeptide of type II procollagen, [CPII]) to cartilage breakdown (Collagen Type II C- telopeptide [CTX-II]). Older adults (N=90; >60 years of age) with tibiofemoral knee OA will be recruited for this study. Participants will be randomly assigned to one of three study groups in equal distributions (n=30 per group). The three groups will include a non-exercise control (CON) group, a concentrically focused resistance training group (CRX; one set/ exercise, two sessions/ week) and an eccentrically focused resistance training group (ERX; one set/ exercise, two sessions/ week). Study measures will be collected at baseline and at month four. Mixed model analyses of covariance will be applied to the outcome variables of the Primary Aim and Secondary Aim 1. Analysis of covariance will be applied to the change in cartilage turnover ratios; Pearson correlations adjusted with Bonferroni correction, will be performed to find associations between training induced changes in pain, physical function and cartilage turnover. The findings from this novel study will be used to further develop optimal strengthening prescriptions to treat knee OA and prevent continued cartilage breakdown. PUBLIC HEALTH RELEVANCE: Osteoarthritis elicits quadricep muscle deficits and cartilage breakdown, both of which contribute to pain and functional impairment in the older adult. A possible method to combat these disease processes is resistance exercise training. This project will examine whether there are differential improvements in osteoarthritis symptoms, impairment and cartilage turnover using a novel eccentric resistance exercise program compared with concentric focused resistance exercise in older persons.