Endurance limit is essential for intermittent physical operations, as physical task designs with inappropriate endurance estimation could potentially lead to work-related musculoskeletal disorders (WMSDs). Here, we propose a general approach to estimate the endurance limits of the duration and workload in intermittent operations, namely the endurance time (ET) and maximum acceptable exertion (MAE). This general endurance limit approach was developed based on physiology-based muscle fatigue and recovery models, considering task parameters and individual fatigue attributes. This approach was preliminarily validated by (1) conducting experimental studies to check the feasibility of predicting individual and group ETs in simplified isometric intermittent operations, and (2) demonstrating its utility in interpreting existing empirical MAE models and their experimental results. The findings suggest that the proposed model offers a promising approach to estimate the endurance limits in intermittent physical operations, and could help future studies aimed at modeling the relationship between endurance limits and intermittent task characteristics.

中文翻译：

---

估计间歇性任务耐力极限的新方法

耐力极限对于间歇性身体操作至关重要，因为不恰当的耐力估计的身体任务设计可能会导致与工作相关的肌肉骨骼疾病 (WMSD)。在这里，我们提出了一种通用方法来估计间歇操作中持续时间和工作量的耐力极限，即耐力时间（ET）和最大可接受运动量（MAE）。这种一般的耐力极限方法是基于基于生理学的肌肉疲劳和恢复模型开发的，考虑了任务参数和个人疲劳属性。该方法通过 (1) 进行实验研究以检查在简化的等距间歇操作中预测单个和组 ET 的可行性，初步验证了该方法，(2) 证明其在解释现有经验 MAE 模型及其实验结果方面的效用。研究结果表明，所提出的模型为估计间歇性物理操作中的耐力极限提供了一种有前途的方法，并有助于未来旨在模拟耐力极限与间歇性任务特征之间关系的研究。