Finger Coordination in Elderly

描述（由申请人提供）：我们最近的研究表明，有充分证据表明，肌肉力量的下降及其随年龄变化的增加伴随着手/手指控制的更微妙的变化。特别是，高龄与在手持物体上产生高强度和准确时间轮廓的手指力的能力受损有关。最近的研究还表明，旋转动作的控制与专门的多指协同作用有关。基于这些发现，我们提出了六个与旋转动作中涉及的多指协同作用的年龄相关变化相关的假设。三个有老年人和年轻人参与的实验将通过代表日常使用手的典型情况的任务来研究多位数协同作用：“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）。我们将分析这些任务表现的可变性，并量化涉及握/压和旋转任务组件的多位数协同作用。三个实验将研究在手持式物体自主旋转之前，在自触发负载/扭矩扰动之前，以及对意外扰动的响应之前，多数字协同作用的调整。最后的实验将研究八周的力量训练对两种多指任务表现的影响，并量化涉及抓握和旋转任务组件的多指协同作用的变化。我们还将量化培训后6个月的培训效果。我们将使用两种类型的运动，其中一种是专门针对手部内在肌肉的，在我们早期的研究中，这些肌肉显示出与年龄有关的力量下降。实验结果指标将与四项临床功能测试的表现进行比较。拟议的研究将在量化与年龄相关的多指协同作用损伤方面是独一无二的，这些损伤稳定了手旋转动作及其与手功能的关系。最后一项研究可能对老年人手部运动的优化有潜在的启示。

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.