Macaque Model of Carpal Tunnel Syndrome: Effects of Force and Posture Exposures

描述（由申请人提供）：本研究的长期目标是减少与工作相关的腕管综合征（CTS）的发生。为了实现这一目标，我们需要完善我们对工作环境中物理因素（力量、任务持续时间、姿势和重复）对障碍发展的贡献的理解。最终，我们的目标是1)描述各种物理暴露（力量，重复等）与慢性过度使用导致的CTS发展之间的关系；2)了解损伤和恢复周期；3)了解物理暴露的改变在多大程度上可以预防CTS的发展或复发。我们之前开发并使用了一种新的非人灵长类动物模型来证明慢性过度使用与手腕中位单神经病变（Dx与CTS密切相关）的发病之间存在直接联系。在这个应用中，我们建议应用这种新颖的方法来量化选择的工作暴露和障碍发展之间的关系。本应用程序的具体目的是：1)量化力和手腕姿势对改变CTS预期发展的综合影响；2)量化与CTS自然恢复相关的恢复期；3)扩展我们的猕猴最大自主捏用力数据库，我们使用它来预测和设置我们协议中的实验力水平（最大的百分比）。研究设计和方法：束状猕猴将接受训练，以执行重复性的掐食任务。任务绩效数据将被连续测量：施加的力，捏捏的数量和持续时间，捏捏之间的间隔。每两周对工作手和非工作手的感觉神经传导速度（SNCV）进行评估。在18周的暴露期内，将使用纵向组间设计来研究捏紧力和手腕姿势的影响，以表征每个因素对导致的正中神经损伤的影响。累积工作量、损伤程度、发生时间是用来描述暴露因素和结果之间关系的一些依赖度量。MRI将在基线、任务暴露结束时和恢复时收集，以量化神经形态学的变化。低和高的暴露水平将使我们能够探索暴露阈值可能在哪里。我们还建议扩大我们的猕猴意志强度数据库，这将是未来研究的资源（我们和其他研究团队）。与公共卫生的相关性：慢性疲劳综合症在一些工人群体中发病率很高，平均每个病例损失28个工作日，使这一疾病对雇员和雇主来说代价高昂。我们之前的研究证实，CTS可能是由于过度使用双手造成的。现在我们需要根据神经损伤的程度来区分不同的暴露程度，这样，从长远来看，与工作有关的CTS的发展或复发的风险就可以降低。

DESCRIPTION (provided by applicant): The long term objective of this research is to reduce occurrence of work-related Carpal Tunnel Syndrome (CTS). In pursuit of this goal we need to refine our understanding of the contribution of physical factors in the work environment (force, task duration, posture and repetition) to development of the disorder. Ultimately we aim to 1) characterize associations between various physical exposures (force, repetition, etc) and development of CTS due to chronic overuse; 2) understand injury and recovery cycles; and 3) learn the degree to which modification of physical exposures can prevent CTS development or recurrence. We have previously developed and used a new non-human primate model to demonstrate a direct link between chronic overuse and onset of median mononeuropathy at the wrist (Dx closely associated with CTS). In this application we propose to apply this novel approach to quantifying relationships between selected work exposures and disorder development. The specific aims of this application are to: 1) To quantify the combined effects of force and wrist posture in altering the expected development of CTS; 2) To quantify the recovery period associated with a natural recovery from CTS; and 3) To expand our database of maximum voluntary pinch exertion force of the macaque, which we use to predict and set experimental levels of force (as % of maximum) in our protocols. Research design and methods: Macaca fascicularis monkeys will be trained to perform a repetitive pinching task for daily food rations. Task performance data will be measured continuously: force exerted, quantity and duration of pinches, and intervals between pinches. Every two weeks Sensory Nerve Conduction Velocity (SNCV) will be assessed in the working and the non-working hand. Effects of pinch force and wrist posture will be studied using a longitudinal, between group design to characterize effect of each factor on resulting median nerve impairment, over a 18-week exposure period. Cumulative workload, degree of impairment, time to occurrence are some of the dependent measures that will be used to characterize the association between exposure factors and outcomes. MRI will be collected at baseline, at end of task exposure, and at point of recovery, to quantify change in nerve morphology. Low and higher exposure levels will allow us to explore where exposure thresholds might lay. We also propose to expand our database of macaque volitional strength, which will be a resource for future research (ours and other research teams). Relevance to public health: CTS occurs at high rates in some worker populations with a median of 28 lost work days per case, making this a disorder that is costly for employees and employers. Our previous work confirms that CTS can result from overuse of the hands. Now we need to differentiate amongst exposures, in terms of extent of nerve impairment, so that, in the long term, the risk for development or recurrence of work- related CTS can be reduced.