Data from: Increasing cognitive load attenuates right arm swing in healthy human walking

Human arm swing looks and feels highly automated, yet it is increasingly apparent that higher centres, including the cortex, are involved in many aspects of locomotor control. The addition of a cognitive task increases arm swing asymmetry during walking, but the characteristics and mechanism of this asymmetry are unclear. We hypothesized that this effect is lateralized and a Stroop word-colour naming task—primarily involving left hemisphere structures—would reduce right arm swing only. We recorded gait in 83 healthy subjects aged 18–80 walking normally on a treadmill and while performing a congruent and incongruent Stroop task. The primary measure of arm swing asymmetry—an index based on both three-dimensional wrist trajectories in which positive values indicate proportionally smaller movements on the right—increased significantly under dual-task conditions in those aged 40–59 and further still in the over-60s, driven by reduced right arm flexion. Right arm swing attenuation appears to be the norm in humans performing a locomotor-cognitive dual-task, confirming a prominent role of the brain in locomotor behaviour. Women under 60 are surprisingly resistant to this effect, revealing unexpected gender differences atop the hierarchical chain of locomotor control.

人类的手臂摆动在视觉观感与主观体感上均呈现高度自动化的特征，但越来越多的研究证实，包括大脑皮层在内的高级中枢，参与了运动控制的诸多环节。行走时附加认知任务会加剧手臂摆动的不对称性，但该不对称性的特征与内在机制仍不明晰。我们提出如下假说：该效应具有偏侧性，且主要激活左侧大脑半球结构的Stroop色词命名任务（Stroop word-colour naming task），仅会抑制右侧手臂摆动。本研究招募了83名年龄介于18至80岁的健康受试者，记录其在跑步机上自然行走，以及分别执行一致性、不一致性Stroop任务时的步态数据。手臂摆动不对称性的核心衡量指标——基于三维手腕运动轨迹构建的指数（正值表示右侧手臂运动幅度成比例更小）——在双任务条件下，于40至59岁的受试者中显著升高，而在60岁以上人群中该升高幅度进一步加大，这一现象由右侧手臂屈曲幅度降低所驱动。在执行运动-认知双任务的人群中，右侧手臂摆动减弱似乎是普遍现象，这证实了大脑在运动行为中发挥着关键作用。60岁以下的女性对该效应表现出出人意料的抵抗性，这揭示了运动控制层级调控链中此前未被发现的性别差异。