Hooyman Andrew, Wang Peiyuan, Schaefer Sydney Y
School of Biological and Health Systems Engineering, Arizona State University, 501 E. Tyler Mall, MC 9709, Tempe, AZ, 85287, USA.
Exp Brain Res. 2021 May;239(5):1617-1626. doi: 10.1007/s00221-021-06084-x. Epub 2021 Mar 24.
Age-related declines in fine motor control may impact tool-use and thereby limit functional independence. Most previous research has, however, focused on the effect of aging on gross motor tasks. Few studies have investigated the effects of aging on the strategy or quality of fine motor skills, especially in tool-use, which may better reflect how age impacts complex movement capability. Twenty-two young (ages 19-35) and 18 older adults (ages 58-87) performed a timed upper extremity task using a tool to acquire and transport objects to different locations. Overall task performance was divided into two phases based on 3-D position of the tool: a gross motor phase (object transport) and a fine motor phase (object acquisition). Overall, older adults took longer to complete the task. A linear model indicated that this was due to the duration of the fine motor phase more so than the gross motor phase. To identify age-related differences in the quality of the fine motor phase, we fit three-dimensional ellipsoids to individual data and the calculated the ellipsoid volume. Results demonstrated a significant volume-by-age interaction, whereby increased ellipsoid volume (space the tool occupied) related to increased mean dwell time for the older adult group only; younger adults did not demonstrate this relationship. Additionally, older adults with longer movement times during the fine motor phase also had lower cognitive scores. No age-related differences were observed for the gross motor phase, suggesting that age-related declines in tool-use may be due to changes in fine motor control and cognitive status.
与年龄相关的精细运动控制能力下降可能会影响工具使用，从而限制功能独立性。然而，以前的大多数研究都集中在衰老对粗大运动任务的影响上。很少有研究调查衰老对精细运动技能的策略或质量的影响，特别是在工具使用方面，这可能更好地反映年龄如何影响复杂运动能力。22名年轻人（19 - 35岁）和18名老年人（58 - 87岁）使用工具执行一项定时上肢任务，将物体获取并运送到不同位置。根据工具的三维位置，将整体任务表现分为两个阶段：粗大运动阶段（物体运输）和精细运动阶段（物体获取）。总体而言，老年人完成任务所需时间更长。线性模型表明，这更多是由于精细运动阶段的持续时间，而非粗大运动阶段。为了确定精细运动阶段质量的年龄相关差异，我们将三维椭球体拟合到个体数据并计算椭球体体积。结果显示出显著的体积与年龄交互作用，即仅老年组椭球体体积增加（工具占据的空间）与平均停留时间增加相关；年轻人未表现出这种关系。此外，在精细运动阶段运动时间较长的老年人认知得分也较低。在粗大运动阶段未观察到年龄相关差异，这表明与年龄相关的工具使用能力下降可能是由于精细运动控制和认知状态的变化。
