Stenlund T C, Lundström R, Lindroos O, Häger C K, Burström L, Neely G, Rehn B
Dept. of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Sweden.
Dept. of Public Health and Clinical Medicine, Occupational Medicine, Umeå University, Sweden; Dept. of Radiation Sciences, Biomedical Engineering, Umeå University, Sweden.
J Electromyogr Kinesiol. 2015 Jun;25(3):548-56. doi: 10.1016/j.jelekin.2015.03.002. Epub 2015 Mar 17.
Driving on irregular terrain will expose the driver to sideways mechanical shocks or perturbations that may cause musculoskeletal problems. How a cognitive task, imposed on the driver, affects seated postural reactions during perturbations is unknown. The aim of the present study was to investigate seated postural reactions in the neck and trunk among healthy adults exposed to sideways perturbations with or without a cognitive task. Twenty-three healthy male subjects aged 19-36 years, were seated on a chair mounted on a motion system and randomly exposed to 20 sideways perturbations (at two peak accelerations 5.1 or 13.2m/s(2)) in two conditions: counting backwards or not. Kinematics were recorded for upper body segments using inertial measurement units attached to the body and electromyography (EMG) was recorded for four muscles bilaterally in the neck and trunk. Angular displacements (head, neck, trunk and pelvis) in the frontal plane, and EMG amplitude (normalised to maximum voluntary contractions, MVC) were analysed. The cognitive task provoked significantly larger angular displacements of the head, neck and trunk and significantly increased EMG mean amplitudes in the upper neck during deceleration, although 10% of MVC was never exceeded. A cognitive task seems to affect musculoskeletal reactions when exposed to sideways perturbations in a seated position.
在不规则地形上驾驶会使驾驶员受到侧向机械冲击或扰动，这可能会导致肌肉骨骼问题。施加在驾驶员身上的认知任务如何影响扰动期间的坐姿反应尚不清楚。本研究的目的是调查在有或没有认知任务的情况下，健康成年人在受到侧向扰动时颈部和躯干的坐姿反应。23名年龄在19 - 36岁之间的健康男性受试者坐在安装在运动系统上的椅子上，在两种情况下随机接受20次侧向扰动（在两个峰值加速度5.1或13.2m/s²）：倒着数数或不数。使用附着在身体上的惯性测量单元记录上身节段的运动学数据，并双侧记录颈部和躯干四块肌肉的肌电图（EMG）。分析额面内的角位移（头部、颈部、躯干和骨盆）以及EMG幅度（相对于最大自主收缩，MVC进行归一化）。尽管从未超过MVC的10%，但认知任务在减速期间引发了头部、颈部和躯干明显更大的角位移，并显著增加了上颈部的EMG平均幅度。当坐姿时受到侧向扰动时，认知任务似乎会影响肌肉骨骼反应。
