Data from: The combined fatigue effects of sequential exposure to seated whole body vibration and physical, mental, or concurrent work demands

Many occupations in agriculture, construction, transportation, and forestry are non-routine, involving non-cyclical tasks, both discretionary and non-discretionary work breaks, and a mix of work activities. Workers in these industries are exposed to seated whole body vibration (WBV) and tasks consisting of physical, mental, or a combination of demands. Risk assessment tools for non-routinized jobs have emerged but there remains a need to understand the combined effects of different work demands to improve risk assessment methods and ultimately inform ergonomists and workers on optimum work arrangement and scheduling strategies. The objective of this study was to investigate fatigue-related human responses of WBV sequentially combined with physical, mental, or concurrent physical and mental demands. Sixteen healthy participants performed four conditions on four separate days: (1) physically demanding work, (2) mentally demanding work, (3) concurrent work, and (4) control quiet sitting. For each condition, participants performed two 15-minute bouts of the experimental task, separated by 30-minutes of simulated WBV based on realistic all-terrain vehicle (ATV) riding data. A test battery of fatigue measures consisting of biomechanical, physiological, cognitive, and sensorimotor measurements were collected at four interval periods: pre-session, after the first bout of the experimental task and before WBV, after WBV and before the second bout of the experimental task, and post-session. Nine measures demonstrated statistically significant time effects during the control condition; 11, 7, and 12 measures were significant in the physical, mental, and concurrent conditions, respectively. Overall, the effects of seated WBV in combination with different tasks are not additive but possibly synergistic or antagonistic. There appears to be a beneficial effect of seated ATV operation as a means of increasing task variation; but since excessive WBV may independently pose a health risk in the longer-term, these beneficial results may not be sensible as a long-term solution.

农业、建筑、运输与林业等诸多职业均属于非常规作业范畴，其任务具备非周期性特征，包含自主与非自主的工作休息时段，并混合多种工作活动类型。此类行业的从业者会暴露于坐姿全身振动（whole body vibration, WBV）环境中，且工作任务兼具体力、脑力或两者结合的负荷要求。针对非常规作业的风险评估工具虽已问世，但仍需厘清不同工作负荷的联合效应，以优化风险评估方法，最终为人机工程学家与从业者提供最优工作安排与调度策略的参考依据。本研究旨在探究坐姿全身振动分别与体力负荷、脑力负荷，或体力与脑力并发负荷联合作用时，与疲劳相关的人体响应规律。16名健康受试者在4个独立实验日内完成4种实验条件：(1) 体力负荷作业；(2) 脑力负荷作业；(3) 复合负荷作业；(4) 安静坐姿对照。每种条件下，受试者需完成两轮各15分钟的实验任务，两轮任务间隔30分钟的模拟全身振动暴露，该振动基于真实全地形车（all-terrain vehicle, ATV）的行驶数据生成。实验共设置4个时间节点采集疲劳指标成套测试数据，涵盖生物力学、生理、认知及感觉运动类测量指标：实验前、首轮实验任务结束后且全身振动暴露前、全身振动暴露结束后且第二轮实验任务开始前，以及实验结束后。对照条件下共9项指标呈现出显著的时间效应；体力、脑力及复合负荷条件下，分别有11项、7项及12项指标达到统计学显著性水平。总体而言，坐姿全身振动与不同作业任务联合产生的效应并非简单叠加，而是可能呈现协同或拮抗作用。研究显示，作为提升任务多样性的手段，全地形车坐姿操作似乎具备一定益处；但由于长期过度暴露于全身振动可能独立构成健康风险，因此该有益效果不宜作为长期解决方案推广。