National Institute of Occupational Health, Oslo, Norway.
Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, Gävle, Sweden.
Int Arch Occup Environ Health. 2021 May;94(4):647-658. doi: 10.1007/s00420-020-01610-w. Epub 2020 Dec 5.
To determine whether a composite metric of arm elevation and trapezius activity (i.e. neck/shoulder load) is more strongly associated with the 2-year course of neck and shoulder pain intensity (NSPi) among construction and healthcare workers than each exposure separately.
Dominant arm elevation and upper trapezius muscle activity were estimated in construction and healthcare employees (n = 118) at baseline, using accelerometry and normalized surface electromyography (%MVE), respectively. At baseline and every 6 months for 2 years, workers reported NSPi (score 0-3). Compositions of working time were determined for arm elevation (< 30°; 30-60°; > 60°), trapezius activity (< 0.5%; 0.5-7.0%; > 7.0%MVE), and a composite metric "neck/shoulder load" (restitution, low, medium, and high load). Associations between each of these three compositions and the 2-year course of NSPi were determined using linear mixed models.
Associations between exposure compositions and the course of NSPi were all weak and in general uncertain. Time spent in 0.5-7.0%MVE showed the largest and most certain association with changes in NSPi during follow-up (β = - 0.13; p = 0.037; corresponding to a -0.01 change in NPSi every 6 months). Among pain-free workers at baseline, medium (β = - 0.23; p = 0.039) and high (β = 0.15; p = 0.031) neck/shoulder load contributed the most to explaining changes in NSPi.
The composite metric of neck/shoulder load did not show a stronger association with the course of NSPi than arm elevation or trapezius activity alone in the entire population, while some indications of a stronger association were found among those who were pain-free at baseline.
确定手臂抬高和斜方肌活动（即颈部/肩部负荷）的综合指标与建筑和医疗保健工人颈部和肩部疼痛强度（NSPi）的 2 年病程之间的相关性是否强于单独的每种暴露。
使用加速度计和归一化表面肌电图（%MVE）分别在基线时估计建筑和医疗保健员工（n=118）的主导手臂抬高和上斜方肌肌肉活动。在基线和 2 年内每 6 个月，工人报告 NSPi（评分 0-3）。确定手臂抬高（<30°; 30-60°;>60°）、斜方肌活动（<0.5%; 0.5-7.0%;>7.0%MVE）和综合指标“颈部/肩部负荷”（复位、低、中、高负荷）的工作时间构成。使用线性混合模型确定这三个组成部分中的每一个与 NSPi 的 2 年病程之间的关联。
暴露成分与 NSPi 病程之间的关联均较弱且总体不确定。0.5-7.0%MVE 时间的比例与随访期间 NSPi 的变化相关性最大且最确定（β=-0.13;p=0.037;相当于每 6 个月 NPSi 变化-0.01）。在基线时无疼痛的工人中，中等（β=-0.23;p=0.039）和高（β=0.15;p=0.031）颈部/肩部负荷对解释 NSPi 的变化贡献最大。
在整个人群中，颈部/肩部负荷的综合指标与 NSPi 的病程相关性并不强于手臂抬高或斜方肌活动单独，而在基线时无疼痛的人群中则存在更强关联的一些迹象。
