Carpal Kinematics During Functional Tasks

描述(由申请人提供)：影响上肢的与工作相关的肌肉骨骼疾病是一个重要且代价高昂的国家健康问题。生物力学负荷已被认为是肌肉骨骼疾病发展的关键因素。这项建议侧重于手腕和前臂远端在功能任务中的骨骼力学。尽管飞镖运动员的名字听起来微不足道，但飞镖运动员的运动(DTM)--手腕从放射状伸展到尺骨屈曲，与解剖轴线倾斜--已被确定为手腕较重要的功能性运动之一，对锤击和投掷等任务至关重要。身体研究和我们最近的活体工作都表明，飞镖投手的运动是通过腕骨近端骨骼的最小运动来完成的。在飞镖投掷运动员的运动中，近侧排的这种独特的缺乏运动表明，腕中关节必须用其他独特的运动模式来补偿，尽管到目前为止还没有研究过这一点。这项建议的最终目标是评估在与工作场所相关的肌肉骨骼损伤相关的高需求任务期间腕关节的变化。我们的第一个目标是确定在模拟锤击任务中腕部的八块腕骨和远端尺桡骨关节(DRUJ)的运动学(运动和姿势/构象)。在第二个目标中，我们将在身体模型中检查同样的运动，这将首次允许直接比较体内和体外的腕骨力学。关于上肢的功能和负荷，一个特别耐人寻味的问题是，腕部如何对体内的拉伸负荷做出反应，例如当搬运重物或使用扳手拧紧螺栓时产生的拉伸负荷。一种可能性是腕骨没有承受张力，因为前臂肌肉的收缩抵消了拉伸负荷。因此，在这项建议的第三个目标中，我们将确定在前臂肌肉系统激活和不激活的情况下，拉伸负荷如何影响腕骨。由于在功能加载期间推送任务的重要性，在第三个目标中也将检查压缩任务。这项工作的意义在于，它将提供迄今为止在活体中无法获得的关于功能任务期间腕关节和DRUJ的力学数据。我们的发现将对工作场所人体工程学领域产生深远的影响，并将提供重要的基础科学数据，医生和科学家可以利用这些数据来制定伤害预防策略和合理的康复方案。这项建议使用先进的活体成像技术，首次在人类受试者中测量功能任务和负荷对复杂的腕部骨骼解剖的运动和形态的影响。了解腕骨和前臂远端的功能对于减少与工作相关的上肢肌肉骨骼疾病至关重要。

DESCRIPTION (provided by applicant): Work-related musculoskeletal disorders affecting the upper extremity are an important and costly national health problem. Biomechanical loading has been identified as a critical factor in the development of musculoskeletal disorders. This proposal focuses on the skeletal mechanics of the wrist and distal forearm during functional tasks. Despite its trivial sounding name, the dart thrower's motion (DTM)-wrist motion from radial extension to ulnar flexion, oblique to the anatomical axes-has been identified as one of the more important functional motions of the wrist, and is critical to tasks such as hammering and throwing. Both cadaver studies and our recent in vivo work suggest that the dart thrower's motion is accomplished with minimal motion of the bones of the proximal row of the carpus. This unique lack of motion of the proximal row during the dart thrower's motion suggests that the midcarpal joints must compensate with other unique patterns of motion, though to date this has not been studied. The ultimate goal of this proposal is to evaluate changes in the carpus during high demand tasks that are associated with workplace related musculoskeletal injury. Our first Aim is to determine the kinematics (motion and posture/conformation) of the eight carpal bones in the wrist and the distal radioulnar joint (DRUJ) during a simulated hammering task. In the second Aim we will examine this same motion in a cadaver model, which for the first time will permit direct comparison of in vivo and in vitro carpal mechanics. An especially intriguing question about the function and loading of the upper extremity is how the carpus responds to tensile loads in vivo, such as those developed when heavy objects are carried or when a wrench is used to tighten a bolt. One possibility is that the carpus is not loaded under tension as contraction of the forearm muscles offsets the tensile loads. Accordingly, in the third Aim of this proposal we will determine how tensile loading affects the carpus, with and without activation of the forearm musculature. A compressive task will also be examined in the third Aim due to the importance of pushing tasks during functional loading. The significance of this work is that it will provide heretofore unavailable in vivo data on the mechanics of the carpus and DRUJ during functional tasks. Our findings will have far reaching implications in the field of workplace ergonomics, and it will provide important basic science data that physicians and scientists can use to develop injury prevention strategies and rational rehabilitation protocols. This proposal uses advanced in vivo imaging techniques to measure, for the first time in human subjects, the effects of functional tasks and loading on the motion and conformation of the complex bony anatomy of the wrist. Understanding how the carpus and distal forearm function is crucial to reducing work-related upper extremity musculoskeletal disorders.