Department of Kinesiology and Physical Education, McGill University, Montreal, Canada.
Feil & Oberfeld/CRIR Research Center, Jewish Rehabilitation Hospital, Laval, Canada.
Biol Sex Differ. 2019 Aug 7;10(1):39. doi: 10.1186/s13293-019-0253-7.
The incidence and prevalence of musculoskeletal disorders (MSDs) is about twice as high in women compared to men, and those of the neck/shoulder region are particularly high among women. Fatigue and responses towards pain are known risk factor for MSDs. However, women have been shown to be less fatigable than men, but more sensitive to experimental pain. From a general standpoint, sex differences in the relationships between the fatigue and pain pathways are poorly understood. This may be due to differences in how men and women conceptually define the sensations of fatigue and pain. The objective of this study was to compare physical and verbal descriptors of fatigue and pain between men and women undergoing an experimental protocol where fatigue and pain were manipulated.
Healthy adult volunteers (14 men and 14 women) underwent experimental pain tests to identify pressure pain threshold (PPT) at biceps brachii (BIC), anterior deltoid (AD), and upper trapezius (UT) followed by the Short-form McGill Pain Questionnaire (SF-MPQ) and Pain Catastrophizing Scale (PCS) before and after a repetitive arm task performed at shoulder height until reaching a rating of neck/shoulder perceived exertion, using the Borg Category Ratio 10 (CR10), greater than 8/10. PPT and MPQ data were analyzed using repeated measures analyses of variance (ANOVA) (time × sex). Correlational analyses were used to investigate relationships between pain measures with time and fatigue.
UT PPT was reduced following the fatiguing task (p ≤ 0.01). Men overall reported higher AD PPT levels compared to women (p ≤ 0.05). MPQ and PCS magnification scores were significantly higher after the fatiguing task (p ≤ 0.05), with no sex differences. Time to fatigue correlated with changes in AD PPT in men and with PCS scores in women.
Findings suggest that mechanisms underlying the sensation of acute pain following a repetitive shoulder height task are closely linked with PPT changes in shoulder stabilizers (UT) irrespective of sex, and more so with physical pain responses in men and in attitudes towards pain in women. Sex differences in pain perception may contribute to a better understanding of sex-specific mechanisms underlying neck/shoulder MSDs.
与男性相比，肌肉骨骼疾病（MSD）在女性中的发病率和患病率高出约两倍，而颈部/肩部区域的 MSD 尤其高发。疲劳和对疼痛的反应是 MSD 的已知危险因素。然而，女性的疲劳耐受性低于男性，但对实验性疼痛更敏感。从一般角度来看，疲劳和疼痛通路之间的性别差异关系知之甚少。这可能是由于男性和女性在概念上对疲劳和疼痛感觉的定义不同所致。本研究的目的是比较男性和女性在经历疲劳和疼痛被人为操纵的实验方案时对疲劳和疼痛的身体和口头描述。
健康的成年志愿者（14 名男性和 14 名女性）接受了实验性疼痛测试，以确定肱二头肌（BIC）、前三角肌（AD）和上斜方肌（UT）的压力疼痛阈值（PPT），然后在进行重复手臂任务之前和之后使用短格式麦吉尔疼痛问卷（SF-MPQ）和疼痛灾难化量表（PCS）进行评估，手臂任务在肩高进行，直到达到颈部/肩部感知的用力程度，使用 Borg 比例 10（CR10）评分大于 8/10。使用重复测量方差分析（ANOVA）（时间×性别）分析 PPT 和 MPQ 数据。使用相关分析来研究疼痛测量值与时间和疲劳之间的关系。
疲劳任务后 UT PPT 降低（p≤0.01）。总体而言，男性 AD PPT 水平高于女性（p≤0.05）。疲劳任务后 MPQ 和 PCS 放大评分显著升高（p≤0.05），但性别无差异。疲劳时间与男性 AD PPT 的变化以及女性 PCS 评分相关。
研究结果表明，重复肩高任务后急性疼痛感觉的机制与肩部稳定器（UT）的 PPT 变化密切相关，而与男性的躯体疼痛反应和女性对疼痛的态度更为相关。疼痛感知的性别差异可能有助于更好地理解颈部/肩部 MSD 背后的特定性别机制。
