Agricultural work is associated with increased risk of adverse musculoskeletal health outcomes. The purpose of this study was to quantify exposure to biomechanical factors among a sample (n = 55) of farmers in the Midwest region of the U.S. while they performed a variety of routine agricultural activities, and to compare exposure levels between these activities. Surface electromyography was used to estimate activity levels of the erector spinae, upper trapezius, forearm flexor, and forearm extensor muscle groups. Simultaneously, inertial sensors were used to measure kinematics of the trunk, upper arm, and wrist. In general, lower muscle activity levels, less extreme postures, and slower movement speeds were observed during activities that involved primarily the use of agricultural machinery in comparison to manual activities, suggesting a potential advantage of mechanization relative to musculoskeletal health. Median wrist movement speeds exceeding recently proposed exposure thresholds were also observed during many manual activities, such as milking animals and repairing equipment. Upper arm postures and movement speeds did not appear to confer excessive risk for shoulder-related outcomes (on the whole), but interpretation of the results is limited by a sampling approach that may not have captured the full extent of exposure variation. Not surprisingly, substantial variation in exposure levels were observed within each agricultural activity, which is related to substantial variation in the equipment, tools, and work practices used by participants. Ultimately, the results of this study contribute to an emerging literature in which the physical demands of routine agricultural work have been described on the basis of sensor-based measurements rather than more common self-report or observation-based approaches.

中文翻译：

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常见农业活动中的生物力学因素：使用直接测量方法的农场暴露评估结果。

农业工作与肌肉骨骼健康不良后果的风险增加有关。本研究的目的是量化美国中西部地区农民样本 (n = 55) 在进行各种常规农业活动时对生物力学因素的暴露，并比较这些活动之间的暴露水平。表面肌电图用于估计竖脊肌、上斜方肌、前臂屈肌和前臂伸肌群的活动水平。同时，惯性传感器用于测量躯干、上臂和手腕的运动学。一般来说，与手动活动相比，在主要涉及使用农业机械的活动中观察到较低的肌肉活动水平、较少的极端姿势和较慢的运动速度，表明机械化相对于肌肉骨骼健康的潜在优势。在许多手动活动（例如挤奶和修理设备）中也观察到超过最近提出的暴露阈值的中值手腕运动速度。上臂姿势和运动速度似乎并未给肩部相关结果（总体上）带来过高风险，但对结果的解释受到抽样方法的限制，该方法可能没有捕捉到暴露变化的全部范围。毫不奇怪，在每项农业活动中都观察到暴露水平的显着差异，这与参与者使用的设备、工具和工作实践的显着差异有关。最终，