Smith Ashley, Ritchie Carrie, Warren Jacelle, Sterling Michele
School of Allied Health Sciences, Griffith University, Gold Coast.
Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Canada.
Clin J Pain. 2020 Aug;36(8):601-611. doi: 10.1097/AJP.0000000000000845.
Exercise-induced hypoalgesia (EIH) can be impaired in patients with chronic pain and may be dependent on exercise type. Factors predictive of EIH are not known. This study aimed to: (1) compare EIH in participants with chronic whiplash-associated disorders (WAD) to asymptomatic controls, (2) determine if EIH differs between aerobic and isometric exercise, (3) determine predictors of EIH.
A pre-post study investigated the effect of single sessions of submaximal aerobic treadmill walking and isometric knee extension on EIH in 40 participants with chronic WAD and 30 controls. Pressure pain thresholds were measured at the hand, cervical spine, and tibialis anterior. Pain intensity, reported previous week physical activity, temporal summation, and conditioned pain modulation (CPM) were measured at baseline.
Participants with WAD demonstrated impaired EIH. Although, the WAD participants demonstrated a partial EIH response (EIH induced at the hand during exercise), no EIH response was found immediately after exercise. There was no difference in EIH between exercise types. In the WAD group, moderate physical activity levels predicted EIH at the hand and high physical activity levels predicted impaired EIH at the neck. More efficient CPM predicted EIH at the hand and less efficient CPM predicted impaired EIH at the neck. These associations were found for isometric exercise only.
Individuals with chronic WAD have impaired EIH with both aerobic and isometric exercise. Higher levels of physical activity and less efficient CPM may be associated with impaired EIH. This may have implications for exercise prescription in this patient group.
慢性疼痛患者的运动诱发痛觉减退（EIH）可能受损，且可能取决于运动类型。目前尚不清楚预测EIH的因素。本研究旨在：（1）比较慢性挥鞭样损伤相关疾病（WAD）参与者与无症状对照组的EIH；（2）确定有氧运动和等长运动之间的EIH是否存在差异；（3）确定EIH的预测因素。
一项前后对照研究调查了单次次极量有氧跑步机行走和等长膝关节伸展对40名慢性WAD参与者和30名对照组EIH的影响。测量手部、颈椎和胫前肌的压痛阈值。在基线时测量疼痛强度、前一周报告的身体活动、时间总和以及条件性疼痛调制（CPM）。
WAD参与者表现出EIH受损。尽管WAD参与者表现出部分EIH反应（运动期间手部诱发的EIH），但运动后立即未发现EIH反应。运动类型之间的EIH没有差异。在WAD组中，中等身体活动水平预测手部的EIH，高身体活动水平预测颈部的EIH受损。更有效的CPM预测手部的EIH，效率较低的CPM预测颈部的EIH受损。这些关联仅在等长运动中发现。
慢性WAD个体在有氧运动和等长运动中均存在EIH受损。较高水平的身体活动和效率较低的CPM可能与EIH受损有关。这可能对该患者群体的运动处方有影响。
