Finger Coordination in Elderly

描述（由申请人提供）：我们最近的研究表明，随着年龄的增长，肌肉力量的下降和变异性的增加伴随着手/手指控制的更微妙的变化。特别是，先进的年龄是与受损的能力，以产生高的幅度和准确的时间配置文件的时刻，手指的力量对手持物体。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。基于这些研究结果，我们制定了六个假设与年龄相关的变化，参与旋转行动的多位数的协同作用。老年人和年轻人参与的三个实验将使用代表日常使用手的典型情况的任务来研究多数字协同作用：“棱镜抓握”（从玻璃杯中喝水），“杠杆抓握”（打开门把手）和“盖子抓握”（转动罐子盖子）。我们将分析这些任务的性能的变化，并量化参与抓/按和旋转任务组件的多位数的协同作用。三个实验将研究多位数协同作用的调整之前，一个手持物体的自愿旋转，在一个自触发的负载/扭矩扰动，并在一个意想不到的扰动。最后的实验将研究8周的力量训练对两个多位数任务的表现的影响，并量化抓握和旋转任务组件中涉及的多位数协同作用的变化。我们还将量化培训后6个月的效果保留。将使用两种类型的运动，其中一种将专门针对手部内在肌肉，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。实验的结果指标将与四项临床功能测试的表现进行比较。拟议的研究将是唯一的量化与年龄有关的障碍的多个数字的协同作用，稳定的手旋转动作及其关系的手功能。最后一项研究将可能对老年人手部运动的优化产生影响。

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.