Finger Coordination in Elderly

描述(申请人提供)：我们最近的研究表明，有充分证据表明，肌肉力量的下降和随年龄增长的变异性伴随着手/手指控制的更微妙的变化。特别是，高龄与产生高强度和准确的手持物体上的力矩的时间分布的能力受损有关。最近的研究还表明，旋转动作的控制与专门的多位数协同作用有关。基于这些发现，我们提出了六个假设，与旋转动作中涉及的多位数协同效应的年龄相关变化有关。针对年长和年轻参与者的三个实验将使用代表手日常使用的典型情况的任务来研究几位数的协同效应：“棱镜抓握”(从杯子里喝水)、“杠杆抓握”(打开门把手)和“抓盖”(转动瓶盖)。我们将分析这些任务性能的变异性，并对握力/按压和旋转任务组件所涉及的多位数协同作用进行量化。三个实验将研究手持物体在自愿旋转之前、在自触发负载/扭矩扰动之前以及在对意外扰动的反应中的多位数协同效应的调整。最后的实验将研究八周的力量训练对两个多位数任务绩效的影响，并量化涉及握力和旋转任务组成部分的多位数协同效应的变化。我们还将在培训后6个月量化培训效果的保留情况。将使用两种类型的锻炼，其中一种将专门针对手部固有肌肉，在我们早期的研究中，这些肌肉显示出与年龄相关的力量下降更大。实验的结果指数将与四项临床功能测试中的表现进行比较。拟议的研究在量化稳定手部旋转动作的多位数协同作用的年龄相关损害及其与手功能的关系方面将是独一无二的。最后一项研究可能对优化老年人的手部锻炼有一定的指导意义。

DESCRIPTION (provided by applicant): Our recent studies have shown that the well-documented drop in muscle force and an increase in its variability with age are accompanied by more subtle changes in the control of the hand/fingers. In particular, advanced age is associated with an impaired ability to produce both high magnitudes and accurate time profiles of moments of digit forces on a hand-held object. Recent research has also shown that the control of rotational actions is associated with specialized multi-digit synergies. Based on these findings, we have formulated six hypotheses related to age-related changes in multi-digit synergies involved in rotational actions. Three experiments with elderly and young participants will study multi-digit synergies using tasks representing typical situations of everyday usage of the hand: "Prismatic grasp" (drinking from a glass), "lever grasp" (opening a door handle), and "lid grasp" (turning a jar lid). We will analyze the variability in the performance of these tasks and also quantify multi-digit synergies involved in the gripping/pressing and rotational task components. Three experiments will study adjustments in multi-digit synergies prior to a voluntary rotation of a hand-held object, prior to a self-triggered load/torque perturbation, and in response to an unexpected perturbation. The final experiment will study effects of eight weeks of strength training on the performance of two multi-digit tasks and quantify changes in multi-digit synergies involved in the gripping and rotational task components. We will also quantify retention of the effects of training 6 months post-training. Two types of exercise will be used, one of which will specifically target intrinsic hand muscles, which have shown a greater age-related drop in force in our earlier studies. Outcome indices of experiments will be compared to performance in four clinical functional tests. The proposed studies will be unique in quantifying age-related impairments of multi-digit synergies that stabilize hand rotational actions and their relations to hand function. The last study will potentially have implications for optimization of hand exercise for elderly.