Larsson B, Rosendal L, Kristiansen J, Sjøgaard G, Søgaard K, Ghafouri B, Abdiu A, Kjaer M, Gerdle B
Rehabilitation Medicine, Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, and Pain and rehabilitation Centre, University Hospital, 581 85 Linköping, Sweden DanTrials A/S, Markvangen 20, DK-2820 Gentofte, Denmark National Research Centre for the Working Environment, Copenhagen, Denmark Institute of Sports Science and Clinical Biomechanics, Campusvej 55, DK-5230 Odense M, Denmark Occupational medicine, Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden Plastic Surgery, Department of Clinical and Experimental Medicine, Linköping University, S-581 85 Linköping, Sweden Sports Medicine Research Unit and Copenhagen Muscle Research Center, Bispebjerg Hospital, Copenhagen, Denmark.
Pain. 2008 Dec;140(3):479-490. doi: 10.1016/j.pain.2008.10.001. Epub 2008 Nov 8.
The trapezius muscle often develops pain as the result of repetitive and stressful work tasks although it is unclear to what extent this pain is due to alterations in muscle concentrations of algesic/nociceptive substances. Twenty women with chronic neck- and shoulder pain (TM) whose work required highly repetitive work tasks and 20 pain-free female colleagues (CON) were studied during and after a full 8-hour workday. We collected microdialysates from their dominant/most painful trapezius muscle; concentrations of serotonin, glutamate, lactate, pyruvate, potassium, bradykinin, and cytokines and blood flow were determined. In addition, we measured surface electromyogram, task exposure level, pain intensity, perceived mental stress, and urine-cortisol. In connection to the clinical neck and shoulder examination, we determined pressure pain thresholds (PPTs) over the trapezius and tibialis muscles. TM had higher concentrations of glutamate (71+/-42 vs. 36+/-15 micromol l(-1)) and pyruvate (187+/-89 vs. 125+/-63 micromol l(-1)) than CON. Interstitial serotonin was higher in TM (before work: 10.6+/-10.8 vs. 2.2+/-1.2 nM; after work: 9.2+/-8.3 vs. 1.5+/-2.9 nM). The trapezius blood flow during the working day was higher in TM than in CON. TM had lower PPT and higher pain intensity throughout the working day. No differences in EMG, task exposure level, mental stress, or urine-cortisol in the groups were found. These findings support the idea that peripheral nociceptive processes are activated in occupationally active subjects, who are diagnosed with trapezius myalgia. In contrast, no sign of low blood flow or increased stress or muscle activity markers were found in TM.
斜方肌疼痛常常是重复性高压力工作任务的结果，不过尚不清楚这种疼痛在多大程度上是由于痛觉/伤害性感受物质的肌肉浓度改变所致。我们对20名患有慢性颈部和肩部疼痛（TM）且工作需要高度重复性任务的女性以及20名无疼痛的女性同事（CON）在完整的8小时工作日期间及之后进行了研究。我们从她们优势侧/疼痛最明显的斜方肌收集了微透析液；测定了血清素、谷氨酸、乳酸、丙酮酸、钾、缓激肽、细胞因子的浓度以及血流量。此外，我们测量了表面肌电图、任务暴露水平、疼痛强度、感知到的精神压力和尿皮质醇。在进行临床颈部和肩部检查时，我们测定了斜方肌和胫骨前肌上的压痛阈值（PPTs）。与CON相比，TM的谷氨酸（71±42对36±15微摩尔/升）和丙酮酸（187±89对125±63微摩尔/升）浓度更高。TM的间质血清素更高（工作前：10.6±10.8对2.2±1.2纳摩尔；工作后：9.2±8.3对1.5±2.9纳摩尔）。工作日期间TM的斜方肌血流量高于CON。在整个工作日中，TM的PPT更低，疼痛强度更高。两组在肌电图、任务暴露水平、精神压力或尿皮质醇方面未发现差异。这些发现支持这样一种观点，即在被诊断为斜方肌肌痛的职业活跃受试者中，外周伤害性感受过程被激活。相比之下，在TM中未发现低血流量、压力增加或肌肉活动标志物增加的迹象。
