Objective

This prospective study assessed the risk of developing rotator cuff syndrome (RCS) with separate or specific combinations of biomechanical exposures measures, controlling for individual confounders.

Background

Compared with other musculoskeletal disorders, rates of work-related shoulder musculoskeletal disorders have been declining more slowly.

Method

We conducted up to 2 years of individual, annual assessments of covariates, exposures, and health outcomes for 393 U.S. manufacturing and healthcare workers without RCS at baseline. Task-level biomechanical exposures assessed exposure to forceful exertions (level, exertion rates, duty cycles), vibration, and upper arm postures (flexion, abduction). Hazard ratios (HRs) were calculated with Cox proportional hazard models.

Results

We observed 39 incident RCS cases in 694 person-years (incidence rate = 5.62 per 100 person-years). Adjusting for confounders, we found increased risk of incident RCS associated with forceful hand exertions per minute for three upper arm posture tertiles: flexion ≥45° (≥28.2% time, HR = 1.11, CI [1.01, 1.22]), abduction ≥30° (11.9–21.2%-time, HR = 1.18, CI [1.04, 1.34]), and abduction >60° (≥4.8% time, HR = 1.16, CI [1.04, 1.29]). We failed to observe statistically significant effects for other interactions or any separate measures of biomechanical exposure.

Conclusion

This study highlights the importance of assessing combinations of exposure to forceful repetition and upper arm elevation when developing interventions for preventing RCS.

Application

Based on these results, interventions that reduce exposure to forceful repetition (i.e., lower force levels and/or slower exertion rates) may reduce the risk of RCS, especially when upper arm elevation cannot be avoided.

中文翻译：

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制造业和医护人员前瞻性研究中肩袖综合征的工作相关风险因素

客观的

这项前瞻性研究通过单独或特定的生物力学暴露措施组合评估了患肩袖综合征 (RCS) 的风险，并控制了个体混杂因素。

背景

与其他肌肉骨骼疾病相比，与工作有关的肩部肌肉骨骼疾病的发病率下降得更慢。

方法

我们对基线时没有 RCS 的 393 名美国制造业和医疗保健工作者进行了长达 2 年的协变量、暴露和健康结果的个人年度评估。任务级别的生物力学暴露评估了对强力运动（水平、运动率、占空比）、振动和上臂姿势（屈曲、外展）的暴露。使用 Cox 比例风险模型计算风险比 (HR)。

结果

我们在 694 人年中观察到 39 起 RCS 事件（发生率 = 5.62/100 人年）。调整混杂因素后，我们发现 RCS 事件的风险增加与三个上臂姿势三分位数的每分钟用力用力相关：屈曲≥45°（≥28.2% 时间，HR = 1.11，CI [1.01, 1.22]），外展≥30 °（11.9–21.2%-时间，HR = 1.18，CI [1.04，1.34]），外展 >60°（≥4.8% 时间，HR = 1.16，CI [1.04，1.29]）。我们未能观察到其他相互作用或任何单独的生物力学暴露测量的统计显着影响。

结论

这项研究强调了在制定预防 RCS 的干预措施时评估暴露于强力重复和上臂抬高的组合的重要性。

应用

基于这些结果，减少用力重复暴露的干预措施（即较低的力量水平和/或较慢的运动速度）可能会降低 RCS 的风险，尤其是当无法避免上臂抬高时。