Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.
ENT Centre of Traunstein, Maxplatz 5, 83278, Traunstein, Germany.
Eur Arch Otorhinolaryngol. 2021 Oct;278(10):3801-3811. doi: 10.1007/s00405-020-06488-5. Epub 2020 Dec 15.
It is still in question whether head oscillation damping during walking forms a part of the vestibular function. The anatomical pathway from the vestibular system to the neck muscles via the medial vestibulospinal tract (MVST) is well known but there is a lack of knowledge of the exact influence and modulation of each other in daily life activities.
(I) We fixed a head-neck unit of a human cadaver specimen in a steal frame to determine the required pitch-torque for a horizontal head position. The mean value of the acquired pitch-torque was 0.54 Nm. (II) On a motorized treadmill we acquired kinematic data of the head, the sternum and both feet by wireless 3D IMUs for seven asymptomatic volunteers. Subsequently three randomized task conditions were performed. Condition 1 was walking without any irritation. Condition 2 imitated a sacculus irritation using a standardized cVEMP signal. The third condition used an electric neck muscle-irritation (TENS). The data were analyzed by the simulation environment software OpenSim 4.0.
8 neck muscle pairs were identified. By performing three different conditions we observed some highly significant deviations of the neck muscle peak torques. Analysing Euler angles, we found during walking a LARP and RALP head pendulum, which also was strongly perturbated.
Particularly the pitch-down head oscillation damping is the most challenging one for neck muscles, especially under biomechanical concerns. Mainly via MVST motor activity of neck muscles might be modulated by vestibular motor signals. Two simultaneous proprioceptor effects might optimize head oscillation damping. One might be a proprioceptive feedback loop to the vestibular nucleus. Another might trigger the cervicocollic reflex (CCR).
头部在行走时的摆动阻尼是否构成前庭功能的一部分仍存在疑问。从前庭系统经由内侧前庭脊髓束（MVST）至颈部肌肉的解剖通路是明确的，但对于日常生活活动中彼此的确切影响和调节知之甚少。
（I）我们将一个人体尸体标本的头颈部单元固定在一个钢框架中，以确定水平头部位置所需的俯仰扭矩。所获得的俯仰扭矩的平均值为 0.54 Nm。（II）在电动跑步机上，我们通过无线 3D IMU 为 7 名无症状志愿者采集了头部、胸骨和双脚的运动学数据。随后进行了三种随机任务条件。条件 1 是无任何刺激的行走。条件 2 使用标准化的 cVEMP 信号模拟球囊刺激。第三种条件使用电颈部肌肉刺激（TENS）。数据由 OpenSim 4.0 仿真环境软件进行分析。
确定了 8 对颈部肌肉。通过执行三种不同的条件，我们观察到颈部肌肉峰值扭矩有一些高度显著的偏差。通过分析欧拉角，我们发现行走时头部会出现 LARP 和 RALP 摆动，这也受到强烈干扰。
特别是在生物力学方面，头部向下摆动的阻尼是颈部肌肉最具挑战性的，特别是在 MVST 运动活动可能会被前庭运动信号调节的情况下。两个同时的本体感受效应可能会优化头部摆动的阻尼。一个可能是向前庭核的本体感受反馈回路。另一个可能引发颈脊反射（CCR）。
