Motor Control Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA.
Brain Behavior Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA.
J Gerontol A Biol Sci Med Sci. 2022 Jul 5;77(7):1405-1412. doi: 10.1093/gerona/glab368.
The ability to grasp and manipulate objects is essential for performing activities of daily living. However, there is limited information regarding age-related behavioral differences in hand sensorimotor function due, in part, to the lack of assessment tools capable of measuring subtle but important differences in hand function. The purpose of this study was to demonstrate performance differences in submaximal force control and tactile pattern recognition in healthy older adults using 2 custom-designed sensorimotor assessment tools.
Sensorimotor function was assessed in 13 healthy older adults (mean age 72.2 ± 5.5 years, range: 65-84 years) and 13 young adults (mean age 20 ± 1.4 years, range: 19-23 years). Clinical assessments included the Montreal Cognitive Assessment (MoCA), monofilament testing, maximum voluntary contraction (MVC), and Grooved Pegboard Test. Sensorimotor assessments included submaximal (5, 20% MVC) grip force step-tracking and tactile pattern recognition tasks.
Clinical assessments revealed no or minimal group differences in MVC, monofilament thresholds, and MoCA. However, sensorimotor assessments showed that older adults took longer to discriminate tactile patterns and had poorer accuracy than young adults. Older adults also produced submaximal forces less smoothly than young adults at the 20% force level while greater variability in force maintenance was seen at 5% but not 20% MVC.
These results demonstrate the ability to integrate higher-order tactile information and control low grip forces is impaired in older adults despite no differences in grip strength or cognition. These findings underscore the need for more sensitive evaluation methods that focus on sensorimotor ability reflective of daily activities.
抓握和操纵物体的能力对于完成日常生活活动至关重要。然而，由于缺乏能够测量手部功能细微但重要差异的评估工具，因此关于年龄相关的手部感觉运动功能行为差异的信息有限。本研究的目的是使用 2 种定制的感觉运动评估工具，证明健康老年人在亚最大力控制和触觉模式识别方面的表现差异。
评估了 13 名健康老年人（平均年龄 72.2±5.5 岁，范围：65-84 岁）和 13 名年轻成年人（平均年龄 20±1.4 岁，范围：19-23 岁）的感觉运动功能。临床评估包括蒙特利尔认知评估（MoCA）、单丝测试、最大自主收缩（MVC）和槽钉板测试。感觉运动评估包括亚最大（5%、20%MVC）握力阶跃跟踪和触觉模式识别任务。
临床评估显示，MVC、单丝阈值和 MoCA 方面，老年人与年轻人之间无差异或差异极小。然而，感觉运动评估表明，老年人识别触觉模式的时间更长，准确性低于年轻人。与年轻人相比，老年人在 20%的力水平下产生的亚最大力不那么平稳，而在 5%但不是 20%MVC 时，力维持的变异性更大。
尽管握力和认知没有差异，但这些结果表明，老年人整合更高阶触觉信息和控制低握力的能力受损。这些发现强调了需要更敏感的评估方法，这些方法侧重于反映日常活动的感觉运动能力。
