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Caneiro J.P.1,2, Smith A.1, O'Sullivan P.1,2, Moseley G.L.3, Lipp O.V.4
1Curtin University, School of Physiotherapy and Exercise Science, Perth, Australia, 2Body Logic Physiotherapy Clinic, Perth, Australia, 3University of South Australia, Adelaide, Australia, 4Curtin University, School of Psychology and Speech Pathology, Perth, Australia
Background: Negative beliefs about back pain and movement are thought to catalyse a cycle of fear-avoidance, pain and disability. People with persistent low back pain (PLBP) commonly report bending and lifting, especially with a 'round-back' as both pain-provoking and fear-provoking. Given the role of beliefs and fear in PLBP, a range of measures, mostly self-report questionnaires, have been developed to interrogate these constructs. However, such measures require conscious reflection, are more susceptible to self-presentation bias and may not reflect implicit, automatic associations. Using a picture-viewing paradigm, we hypothesized that in people with PLBP, high fear of bending with a round-back would be associated with a stronger implicit association between 'danger words' and pictures of a person bending or lifting with a round-back. In addition, people with high fear of bending would display a heightened physiological fear-response to these pictures.
Purpose: This study used personally-relevant stimuli to assess implicit attitudes and physiological fear-response related to fear of bending and lifting with a round-back in participants with PLBP with high and low levels of fear of bending with a round-back.
Methods: Forty-four participants completed self-report measures of fear (TSK), anxiety (PASS-20) and disability (RMDQ). Participants were grouped into high and low fear based on self-reported fear of bending with a round-back. Implicit attitudes were assessed by measuring automatic associations between bending and lifting posture (round-back vs straight-back) and perceived danger to the spine in an implicit association task (IAT) and an affective priming task (APT). Physiological fear-response was measured by the eye-blink startle reflex (defensive motivational system), and skin conductance (emotional arousal) in a picture-viewing paradigm.
Results: Participants reported distinct explicit beliefs about bending, with 45.9% reporting bending with a round-back as being dangerous for the back. In contrast, both IAT (0.5, CI [. 3; .6]; p 0.001) and APT (24.2, CI [4.2; 44.3]; p= 0.018) indicated that all participants associated pictures of bending and lifting with a round-back with danger. However, despite the personally-relevant nature of the stimuli, participants with high fear of bending did not show elevated physiological fear-responses (eye-blink startle F (3, 114) =0.4, p=0.721; skin conductance F (3, 126) =0.2, p=0.925) to pictures of bending and lifting in the picture-viewing paradigm.
Conclusion(s): Contrary to our hypothesis, participants with high fear of bending did not display heightened physiological fear-responses, nor stronger implicit associations between danger and images of bending and lifting with a round-back. Our results suggest that, independent of fear level, danger perception related to bending and lifting with a round-back may occur at an automatic level for people with PLBP.
Implications: Perceived danger of bending and lifting with a round-back may be an underlying implicit attitude held by all people with PLBP. Our results suggest that self-report measures may not be sufficient to identify fears about specific threatening movements. Considering the proposed role of automatic cognitions on behavioural intention, future studies are needed to investigate the influence of implicit beliefs on behaviour, and if they are amenable to change with targeted interventions.
Funding acknowledgements: JP Caneiro is supported by an Australian Postgraduate Award (APA) and Curtin University Postgraduate (CUPS) Scholarships.
Topic: Musculoskeletal: spine
Ethics approval: The study was approved by Curtin University´s Human Research Ethics Committee - Faculty of Health Sciences of (approval number: HR157/2015).
All authors, affiliations and abstracts have been published as submitted.
