The relation of altered pain processing to impact loading and response to a gait retraining treatment in knee osteoarthritis

项目摘要/摘要 膝骨性关节炎(OA)是一个重大的公共卫生问题，会导致严重的疼痛和功能限制， 然而，几乎没有有效的治疗方法来改善疼痛和功能。需要非侵入性治疗 提高生活质量，减少对全膝关节置换术的需求。异常机械载荷是一种 膝骨性关节炎的病因已为人所熟知，许多康复治疗的目的是改善异常负荷。 冲击负荷就是这样一个因素，可以通过干预来潜在地改善疼痛和功能。而当 步态再训练策略已被证明能改善膝关节内收瞬间，目前尚不清楚步态是否 在患有膝骨性关节炎的老年患者中，再训练可以改变冲击负荷，改善膝关节疼痛。具有以下特征的个人 疼痛的膝骨性关节炎也表现出对正常的非疼痛刺激(即敏化)的高度反应。 以及对疼痛的下行抑制受损，这两者都会导致更严重的疼痛。它是未知的， 然而，感觉神经系统的这些变化是否也会影响运动传出神经 系统，从而对运动功能产生不利影响。此外，疼痛处理过程的改变 可能会改变传统康复策略的效果。这样的洞察力将为 量身定制个人康复策略。拟议工作的具体目标是：1)评估 与膝关节疼痛严重程度无关的改变的疼痛处理与冲击负荷(例如，峰值冲击)的关系 力和负荷率由地面反作用力)在行走过程中，2)确定是否进行步态再训练 方案减少了膝盖骨关节炎患者的冲击负荷和膝关节疼痛，以及3)确定 改变的疼痛处理改变了步态再训练对冲击负荷的影响。为了实现具体目标1，我们将 利用美国国立卫生研究院资助的多中心骨关节炎研究(MOST)的数据，这是一项约3000人的队列研究 患有或有膝骨性关节炎风险的个人，其中疼痛敏感度和地面反应力的测量 对步态过程中的(GRF)进行了评估。冲击载荷的测量将根据GRFS确定。为 具体目标2和3，受试者将在当地招募，并接受生物力学和疼痛评估 基线和随访。受试者将被随机分为对照步行干预组和步行干预组 步态再训练计划。再培训将包括口头反馈，以柔化脚步和实时视觉 在步行时使用加速度计进行反馈以降低胫骨加速度(膝关节负荷的相关性) 一台跑步机。主要和次要结果分别包括冲击负荷和膝关节疼痛的测量。 这项拟议的研究具有重要意义，因为它将直接影响个人的临床管理。 膝盖骨关节炎。这项提议将为Stefan ik博士提供疼痛神经生物学方面的新培训和指导， 生物力学和运动分析方法，步态再训练和进行临床干预研究， 这是建立在他之前的临床流行病学研究经验的基础上的。这一培训将是 协助Stefan ik博士实现开发新颖有效的康复治疗的长期职业目标 膝骨性关节炎患者的干预措施。

PROJECT SUMMARY/ABSTRACT Knee osteoarthritis (OA) is a major public health problem, causing substantial pain and functional limitations, yet few effective therapies are available to improve pain and function. Non-invasive treatments are needed to improve quality of life and decrease the need for total knee arthroplasty. Abnormal mechanical loading is a well-recognized cause of knee OA and many rehabilitation treatments aim to improve abnormal loading. Impact loading is one such factor that can be intervened upon to potentially improve pain and function. While gait retraining strategies have been shown to improve the knee adduction moment, it is unknown if gait retraining can change impact loading and improve knee pain in older individuals with knee OA. Individuals with painful knee OA also demonstrate a heightened response to normally non-painful stimuli (i.e., sensitization) and impaired descending inhibition of pain, both of which contribute to greater pain severity. It is unknown, however, whether these alterations in the sensory nervous system also affect the motor efferent nervous system, with resulting adverse effects on motor function. Furthermore, the presence of altered pain processing may modify the effect of traditional rehabilitation strategies. Such insights would provide opportunities for tailoring individual rehabilitation strategies. The specific aims of the proposed work are: 1) To evaluate the relation of altered pain processing, independent of knee pain severity, to impact loading (e.g., peak impact force and loading rate from the ground reaction force) during walking, 2) To determine whether a gait retraining program decreases impact loading and knee pain in individuals with knee OA, and 3) To determine whether altered pain processing modifies the effect of gait retraining on impact loading. For specific aim 1, we will leverage data from the NIH funded Multicenter Osteoarthritis Study (MOST), a cohort study of ~3000 individuals with or at risk of knee OA, in which measures of pain sensitization and ground reaction forces (GRFs) during gait have been assessed. Measures of impact loading will be determined from GRFs. For specific aim 2 and 3, subjects will be recruited locally and undergo biomechanical and pain assessments at baseline and follow-up. Subjects will be a randomized to either a control walking intervention or a walking program with gait retraining. The retraining will involve verbal feedback to soften footfalls and real-time visual feedback to decrease tibial acceleration (a correlate of knee loading) using an accelerometer while walking on a treadmill. Primary and secondary outcomes include measures of impact loading and knee pain, respectively. The proposed research is highly significant in that it will directly affect the clinical management of individuals with knee OA. This proposal will provide Dr. Stefanik new training and mentorship in the neurobiology of pain, biomechanics and motion analysis methodology, gait retraining and conducting a clinical intervention study, which builds upon his previous research experience in clinical epidemiology. This training will be integral in assisting Dr. Stefanik to meet his long-term career goal of developing novel and effective rehabilitation interventions for individuals with knee OA.