Carpometacarpal Osteoarthritis: Understanding the Intersection of Muscle Mechanics, Joint Instability, and Pain

项目摘要 患有拇指腕掌骨关节炎（CMC OA）的人可能会失去多达50%的手功能。 不幸的是，目前的保守和手术治疗不能提供疼痛缓解，力量和流动性 需要恢复精细和粗大运动功能临床治疗的改进受到缺乏 了解拇指生物力学和肌肉骨骼疼痛之间的复杂关系。在 这项建议，我们解决这个关键的知识差距，通过检查拇指肌肉的作用，在调节 CMC OA的两个主要症状：疼痛和关节不稳定。所有疾病的个体 将研究严重程度和健康对照，以评价仅存在关节不稳定的个体， 疼痛，两者都有，或者都没有。在目标1中，在CMC OA存在下肌肉结构发生何种程度的变化以及如何变化 将评估这些变化对肌肉力量产生能力的影响。收集的数据将包括分册 通过超声成像和拇指肌肉操作范围在体内测量长度和横截面积 通过肌肉骨骼模拟计算。完成这一目标将确定肌肉结构的变化 减轻与加重CMC OA症状，并建立描述健康目标的基线数据 拇指肌肉力量生成参数在目标2中，拇指肌肉活动如何影响疼痛将是 通过整合生物力学技术的实验进行检查（例如，肌电图）和 定量疼痛测试（例如，运动诱发疼痛，定量感觉测试）。实现这一目标将 增强我们对肌肉活动和疼痛之间关系的理解，从而阐明保护性 与CMC OA患者采用的有害代偿性运动策略相比。在目标3中， 将检查拇指肌肉活动对关节稳定性的影响。收集的数据将包括实验数据。 在功能和活动范围期间测量肌肉活动、拇指运动学和拇指动力学 任务以及主动与被动肌肉存在下关节不稳定的生物力学评估 收缩。完成这一目标将确定CMC OA和肌肉活动如何影响CMC关节稳定性， 从而告知临床决定在CMC期间应该（或不应该）如何考虑肌肉 OA治疗。总的来说，这项研究将极大地促进我们对结构和 在CMC OA的存在下拇指肌肉的功能改变。通过评估肌肉力学（目标1），疼痛 (Aim 2）和关节稳定性（目标3）在有和没有CMC OA的个体中，我们将阐明 肌肉力学、症状严重程度和疾病严重程度。这些知识将为当前和未来的 治疗CMC OA，从而改善患有这种疾病的个体的生活质量。

PROJECT SUMMARY Individuals with thumb carpometacarpal osteoarthritis (CMC OA) can lose up to 50% of hand function. Unfortunately, current conservative and surgical treatments do not provide the pain relief, strength, and mobility needed to restore both fine and gross motor function. Improvements in clinical treatments are limited by a lack of understanding regarding the complex relationship between thumb biomechanics and musculoskeletal pain. In this proposal, we address this critical knowledge gap by examining the role of thumb muscles in modulating the two primary symptoms of CMC OA: pain and joint instability. Individuals across the full spectrum of disease severity and healthy controls will be studied to evaluate individuals who present with only joint instability, only pain, both, or neither. In Aim 1, to what extent muscle structure changes in the presence of CMC OA and how these changes affect muscle force-generating capacity will be evaluated. Collected data will include fascicle length and cross-section area measured in vivo through ultrasound imaging and thumb muscle operating ranges calculated through musculoskeletal simulations. Completion of this aim will identify changes in muscle structure that mitigate versus aggravate CMC OA symptoms and also establish baseline data describing healthy targets for thumb muscle force-generating parameters. In Aim 2, how thumb muscle activity influences pain will be examined through an experiment that integrates biomechanical techniques (e.g., electromyography) and quantitative pain testing (e.g., movement-evoked pain, quantitative sensory testing). Completion of this aim will enhance our understanding the relationship between muscle activity and pain, thereby elucidating protective versus detrimental compensatory movement strategies adopted by individuals with CMC OA. In Aim 3, how thumb muscle activity influences joint stability will be examined. Collected data will include experimental measurements of muscle activity, thumb kinematics, and thumb kinetics during functional and range of motion tasks as well as biomechanical assessments of joint instability in the presence of active versus passive muscle contraction. Completion of this aim will identify how CMC OA and muscle activity influences CMC joint stability, thereby informing clinical decisions regarding how muscles should (or should not) be considered during CMC OA treatment. Overall, this study will critically advance our mechanistic understanding of how the structure and function of thumb muscles change in the presence of CMC OA. By evaluating muscle mechanics (Aim 1), pain (Aim 2), and joint stability (Aim 3) in individuals with and without CMC OA, we will elucidate the co-evolution of muscle mechanics, symptom severity, and disease severity. This knowledge will inform current and future treatment of CMC OA, thereby improving the quality of life of individuals living with this disease.