McDonald Caitlin, Villarejo Mayor John Jairo, Lennon Olive
School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.
Front Bioeng Biotechnol. 2025 Jul 25;13:1605524. doi: 10.3389/fbioe.2025.1605524. eCollection 2025.
Standing up, while one of the most common daily activities is also one of the most mechanically demanding tasks undertaken in daily life. Mobility impairments, in particular neurological conditions, often impede individuals' ability to stand up independently. Despite the obvious association between neurological disorders and impairment of sit-to-stand, the neurophysiological basis of this functional movement is not well understood, particularly at brain level.
Subjects (N = 20, 4 males) performed fifteen sets of five sit-to-stand transitions on an armless, backless seat adjusted to the knee joint height of each participant. Electromyography (EMG) was recorded from the bilateral vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius. Surface electroencephalography (EEG) activity was recorded using eight focused bipolar channels over the sensorimotor cortex. Kinematic data was recorded using a three-dimensional motion capture camera system.
EMG and kinematic data confirm distinct flexion and extension phases of the movement with timed co-activation of the quadriceps and hamstrings, and gastrocnemius and tibialis anterior. EEG data demonstrates a change in cortical activity across the phases of sit-to-stand, notably event-related desynchronisation in the higher band frequencies (14-35 Hz) in the flexion and early extension phase, most prominent at the central Cz electrode. Corticomuscular coherence was observed during the flexion and extension phases between the Cz electrode and the biceps femoris and gastrocnemius, in a subgroup of participants.
This study provides insights into how cortical activity modulates movement execution during sit-to-stand. The event-related spectral perturbation data contributes to our understanding of this movement by revealing frequency specific changes in cortical activity across the phases of the sit-to-stand transition. Corticomuscular coherence was highest during the flexion phase when transitioning to extension, congruent with electroencephalography and Electromyography activity levels. Whether the brain activity observed is sufficient to distinguish between kinematic phases remains to be determined.
站立虽是最常见的日常活动之一，但也是日常生活中对机械要求最高的任务之一。行动障碍，尤其是神经系统疾病，常常会妨碍个体独立站立的能力。尽管神经系统疾病与从坐到站功能受损之间存在明显关联，但这种功能性运动的神经生理基础，尤其是在大脑层面，尚未得到充分理解。
受试者（N = 20，4名男性）在一个无扶手、无靠背的座椅上进行了15组每组5次的从坐到站转换动作，座椅高度根据每位参与者的膝关节高度进行了调整。从双侧股外侧肌、股二头肌、胫前肌和腓肠肌记录肌电图（EMG）。使用八个聚焦双极通道在感觉运动皮层上记录表面脑电图（EEG）活动。使用三维动作捕捉摄像系统记录运动学数据。
肌电图和运动学数据证实了该动作有明显的屈伸阶段，股四头肌和腘绳肌、腓肠肌和胫前肌存在定时协同激活。脑电图数据显示在从坐到站的各个阶段皮层活动有变化，特别是在屈伸阶段较高频段（14 - 35赫兹）出现事件相关去同步化，在中央Cz电极处最为明显。在一组参与者中，观察到在屈伸阶段Cz电极与股二头肌和腓肠肌之间存在皮质肌肉相干性。
本研究深入探讨了皮层活动如何在从坐到站过程中调节运动执行。事件相关频谱扰动数据通过揭示从坐到站转换各阶段皮层活动的频率特异性变化，有助于我们理解这一运动。在从屈曲向伸展过渡的屈曲阶段，皮质肌肉相干性最高，这与脑电图和肌电图活动水平一致。观察到的大脑活动是否足以区分运动学阶段仍有待确定。
