The effect of differential spatiotopic information on the acquisition and generalization of fear of movement-related pain

Fear of movement-related pain significantly contributes to musculoskeletal chronic pain disability. Previous research has shown that fear of movement-related pain can be classically conditioned. That is, in a differential fear conditioning paradigm, after (repeatedly) pairing a neutral joystick movement (conditioned stimulus; CS+) with a painful stimulus (unconditioned stimulus; pain-US), that movement in itself starts to elicit self-reported fear and elevated psychophysiological arousal compared to a control joystick movement (CS−) that was never paired with pain. Further, it has been demonstrated that novel movements that are more similar to the original CS+ elicit more fear than novel movements that are more similar to the CS−, an adaptive process referred to as stimulus generalization. By default, movement/action takes place in reference to the three-dimensional space: a movement thus not only involves proprioceptive information, but it also contains spatiotopic information. Therefore, the aim of this study was to investigate to what extent spatiotopic information (i.e., endpoint location of movement) contributes to the acquisition and generalization of such fear of movement-related pain besides proprioception (i.e., movement direction). In a between-subjects design, the location group performed joystick movements from the middle position to left and right; the movement group moved the joystick from left and right to the middle. One movement (CS+) was paired with pain, another not (CS−). Feature overlap between CSs typically reduces differential learning. The endpoint of both CSs in the movement group is an overlapping feature whereas in the location group the endpoint of both CSs is distinct; therefore we hypothesized that there would be less differential fear learning in the movement group compared to the location group. We also tested generalization to movements with similar proprioceptive features but different endpoint location. Following the principle of stimulus generalization, we expected that novel movements in the same direction as the CS+ but with a different endpoint would elicit more fear than novel movement in the same direction of the CS− but with a different endpoint. Main outcome variables were self-reported fear and pain-US expectancy and eyeblink startle responses (electromyographic). Corroborating the feature overlap hypothesis, the location group showed greater differential fear acquisition. Fear generalization emerged for both groups in the verbal ratings, suggesting that fear indeed accrued to proprioceptive CS features; these effects, however, were not replicated in the startle measures

No differences in return of pain-related fear after extinction and counterconditioning

Extinction-based protocols such as exposure-in-vivo successfully reduce pain-related fear in chronic pain conditions, but return of fear and clinical relapse often occur. Counterconditioning is assumed to attenuate return of fear, likely through changing the negative affective valence of the conditioned stimulus (CS). We hypothesized that counterconditioning would outperform extinction in mitigating return of pain-related fear and decrease CS negative affective valence. Healthy participants performed a conditioning task, in which 2 joystick movements (CSs+) were paired with a painful electrocutaneous stimulus (unconditioned stimulus; pain-US), whereas 2 other movements (CSs-) were not. Subsequently, in the extinction group, 1 CS+ was extinguished (pain-US omission) and the other not, whereas in the counterconditioning group, 1 CS+ was presented with a US of opposite valence (reward-US) and the other was paired with both USs. We tested reinstatement of pain-related fear after 2 unsignalled pain-US presentations. Results showed no group differences in fear reduction and no differences in CS affective valence changes between the extinguished and counterconditioned CS. Remarkably, none of the groups showed reinstatement. Overall, counterconditioning did not appear to be more effective than extinction in reducing pain-related fear and its return. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

Competing goals attenuate avoidance behavior in the context of pain

Current fear-avoidance models consider pain-related fear as a crucial factor in the development of chronic pain. However, pain-related fear often occurs in a context of multiple, competing goals. This study investigated whether pain-related fear and avoidance behavior are attenuated when individuals are faced with a pain avoidance goal and another valued but competing goal, operationalized as obtaining a monetary reward. Fifty-five healthy participants moved a joystick toward different targets. In the experimental condition, a movement to one target (conditioned stimulus [CS+]) was followed by a painful unconditioned stimulus (pain-US) and a rewarding unconditioned stimulus (reward-US) on 50% of the trials, whereas the other movement (nonreinforced conditioned stimulus [CS)) movement was not. In the control condition, the CS+ movement was followed by the pain-US only. Results showed that pain-related fear was elevated in response to the CS+ compared to the CS movement, but that it was not influenced by the reward-US. Interestingly, participants initiated a CS+ movement slower than a CS movement in the control condition but not in the experimental condition. Also, in choice trials, participants performed the CS+ movement more frequently in the experimental than in the control condition. These results suggest that the presence of a valued competing goal can attenuate avoidance behavior. Perspective: The current study provides experimental evidence that both pain and competing goals impact on behavioral decision making and avoidance behavior. These results provide experimental support for treatments of chronic pain that include an individual's pursuit of valuable daily life goals, rather than limiting focus to pain reduction only. (C) 2014 by the American Pain Societ

Development of the Avoidance Daily Activities Photo Scale for Patients With Shoulder Pain

OBJECTIVES: The purpose of this study was to develop the Avoidance of Daily Activities Photo Scale (ADAP shoulder scale) to measure shoulder pain-related avoidance behavior in patients with shoulder pain and evaluate and report the structural validity and internal consistency of the scale. METHODS: Potential daily activities involving the shoulder were selected from the activities and participation domain of the International Classification of Functioning, Disability and Health (ICF). The selected activities were presented to an expert panel, health care professionals, and patients with shoulder pain with the question, "How much do you think it is important to ask patients with shoulder pain about this activity?" Activities attaining a content validity index (CVI) of ≥0.8 were represented using a digitally colored photograph. Activity photographs were evaluated by health care professionals and patients with shoulder pain. Photographs with a CVI of ≥0.8 were included in the scale. To evaluate structural validity and internal consistency of the scale, exploratory factor analysis was performed to determine the presence of any scale domain. Cronbach alpha was calculated to indicate the internal consistency of each domain. RESULTS: Of the 107 preselected activities, 21 attained a CVI of ≥0.8. Eighteen photographs (CVI ≥ 0.8) were included in the scale after being analyzed by 120 health care professionals and 50 patients with shoulder pain. Exploratory factor analysis (N = 156) showed that the ADAP shoulder scale consists of 3 domains: "free movement," "high effort," and "self-care." The internal consistencies of the domains were 0.92, 0.89, and 0.92, respectively. CONCLUSION: The ADAP shoulder scale included 15 photographs distributed in 3 domains. All domains had a high internal consistency. The scale is easily applicable, well understood, and relevant for shoulder pain. IMPACT: The ADAP Shoulder Scale can be used to rate shoulder pain-related avoidance behaviors

Pain Catastrophizing and Fear of Pain predict the Experience of Pain in Body Parts not targeted by a Delayed-Onset Muscle Soreness procedure

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The present study examined whether pain catastrophizing and pain-related fear predict the experience of pain in body regions that are not targeted by an experimental muscle injury protocol. A delayed-onset muscle soreness (DOMS) protocol was used to induce pain unilaterally in the pectoralis, serratus, trapezius, latissimus dorsi, and deltoid muscles. The day after the DOMS protocol, participants were asked to rate their pain as they lifted weighted canisters with their targeted (ie, injured) arm and their nontargeted arm. The lifting task is a nonnoxious stimulus unless participants are already experiencing musculoskeletal pain. Therefore, reports of pain on the nontargeted arm were operationalized as pain in response to a nonnoxious stimulus. Eighty-two healthy university students (54 men, 28 women) completed questionnaires on pain catastrophizing and fear of pain and went through the DOMS protocol. The analyses revealed that catastrophizing and pain-related fear prospectively predicted pain experience in response to a nonnoxious stimulus. The possible mechanisms underlying this effect and clinical implications are discussed