Department of Physical Therapy, School of Health Sciences, Sapporo Medical University, S-1, W-17, Chuo-ku, Sapporo, Hokkaido 060-8556, Japan.
Department of Health Promotion Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan.
Hum Mov Sci. 2024 Dec;98:103291. doi: 10.1016/j.humov.2024.103291. Epub 2024 Sep 20.
To characterize the interference of reactive stepping kinematics related to the increase or maintenance of the number of steps in response to a large perturbation during dual tasks among older adults.
This was a cross-sectional study that included 52 community-dwelling healthy older adults. Reactive stepping performance was analyzed after forward balance loss during a single task and a second cognitive task. The number of steps taken to recover balance and dual-task interference (DTI) for muscular onset latency, anteroposterior (AP) center of pressure (COP) displacement and velocity before step initiation, and step temporal and spatial variables were measured. The DTI of the variables was compared between the participants who increased versus those who maintained the number of steps taken during the dual task relative to the single task.
Twenty-eight (53.8 %) participants increased their steps during dual tasks relative to a single task. In older adults, the AP COP peak velocity (P < 0.001) and step length (P < 0.001) were significantly worse during dual tasks than during a single task. However, this was not observed for older adults who did not increase their steps. The DTI for the AP COP peak velocity and step length were significantly larger for the older adults who increased their steps than those who did not (AP COP peak velocity; P = 0.044, step length; P = 0.003). Both groups showed a significant muscular onset delay during dual tasks than during a single task (P < 0.001), and no significant differences were found between the groups.
Our findings suggest that reactive stepping strategies in older adults after a large external perturbation during secondary cognitive tasks can be attributed to interference with COP control before step initiation and step length.
描述与在双任务中对大外部干扰做出反应时增加或维持步数相关的反应性跨步运动的干扰，这些干扰存在于老年人群中。
这是一项横断面研究，纳入了 52 名社区居住的健康老年人。在单任务和第二次认知任务中发生向前平衡丧失后，分析反应性跨步性能。测量了恢复平衡和双任务干扰（DTI）的步数、肌肉起始潜伏期、前后向（AP）中心压力（COP）位移和速度、跨步时间和空间变量。比较了在双任务中增加与维持与单任务相比的步数的参与者之间的变量 DTI。
28 名（53.8%）参与者在双任务中比在单任务中增加了步数。在老年人中，双任务时的 AP COP 峰值速度（P<0.001）和步长（P<0.001）明显比单任务时差。然而，对于没有增加步数的老年人则没有观察到这种情况。与没有增加步数的老年人相比，增加步数的老年人的 AP COP 峰值速度和步长的 DTI 明显更大（AP COP 峰值速度；P=0.044，步长；P=0.003）。与单任务相比，两组在双任务中都表现出明显的肌肉起始延迟（P<0.001），但两组之间没有发现显著差异。
我们的发现表明，在次要认知任务中发生大外部干扰后，老年人大跨步反应策略可以归因于跨步起始前和步长的 COP 控制受到干扰。
