Aging and Movement Accuracy

老化和运动精度

• 批准号: 6828132
• 负责人: EVANGELOS A CHRISTOU
• 金额: $ 6.03万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6828132
• 关键词: age difference; aging; body movement; clinical research; fingers; goal oriented behavior; human old age (65+); human subject; limb movement; motor neurons; muscle function; neuromuscular system; performance; posture; psychic activity level; psychomotor function; young adult human (21-34)

DESCRIPTION (provided by applicant): NIA Pilot Research Program, Topic 14: Sensory and Motor Processing. Older adults exhibit a reduced ability to perform accurate goal-directed movements with various muscle groups. This impairment is often observed with movements of the index finger and attributed to a reduced capacity to exert consistent movement trajectories (Enoka et al. 2003). Recent findings however, provide evidence that the ability of older adults to match the target movement trajectory with the index finger is impaired despite lower fluctuations (more consistent) in the movement trajectory (Christou et al. 2003). Although the physiological mechanisms that contribute to movement accuracy are largely unexplored, the impaired accuracy in older adults may be due to: (1) inconsistent movement trajectory caused by an altered activation of the motor units in the agonist muscle (2) impaired acceleration of the index finger caused by altered co-activation of the agonist and antagonist muscles. Based on the preliminary findings, it is hypothesized that the reduced accuracy of older adults with goal-directed movements is due to altered levels of co-activation. Two specific aims will test this hypothesis: The first aim will determine the association between fluctuations in movement trajectory and the accuracy of a pointing task with the index finger during interventions that impair (movement speed) or enhance (practice) accuracy in young and older adults. The second aim will establish the contributions of motor unit discharge and co-activation of the agonist and antagonist muscles to the difference in the pointing accuracy. The findings of this RO3 application will constitute novel information on the physiological mechanisms that impair movement accuracy in older adults. These preliminary findings will form the foundation for an RO1 application that will further explore the mechanisms contributing to the impaired movement accuracy in older adults.

描述（由申请人提供）：NIA试点研究计划，主题14：感觉和运动处理。老年人表现出各种肌肉群执行精确目标导向运动的能力降低。这种损伤通常在食指的运动中观察到，并归因于施加一致运动轨迹的能力降低（Enoka等人，2003）。然而，最近的研究结果提供的证据表明，尽管运动轨迹的波动较低（更一致），但老年人将目标运动轨迹与食指匹配的能力受损（Christou等人，2003）。虽然有助于运动准确性的生理机制在很大程度上尚未探索，但老年人的准确性受损可能是由于：（1）由激动肌中运动单元的激活改变引起的不一致的运动轨迹（2）由激动肌和拮抗肌的共同激活改变引起的食指加速受损。根据初步的研究结果，我们假设老年人目标导向运动的准确性降低是由于共激活水平的改变。两个具体的目标将测试这一假设：第一个目标将确定运动轨迹的波动与食指指向任务的准确性之间的关联，在干预期间，损害（运动速度）或增强（练习）年轻人和老年人的准确性。第二个目标将建立运动单位放电和共同激活的激动剂和拮抗剂肌肉的指向精度的差异的贡献。这一RO3应用的发现将构成关于损害老年人运动准确性的生理机制的新信息。这些初步研究结果将为RO1应用奠定基础，进一步探索导致老年人运动准确性受损的机制。