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Carvalho F.A.1, Maher C.G.2, Franco M.R.1, Morelhão P.K.1, Oliveira C.B.1, Silva F.G.1, Pinto R.Z.1
1Sao Paulo State University (UNESP), Physiotherapy, Presidente Prudente, Brazil, 2The George Institute for Global Health, Musculoskeletal, Sydney, Australia
Background: The fear-avoidance model postulates that higher pain-related fear is associated with the development of avoidance behavior and has been shown to be an important predictor of chronicity in patients with LBP. Tampa Scale of Kinesiophobia (TSK) scores and perceived disability measures have shown fair to moderate correlations in patients with chronic LBP. However, the relationship between fear of movement and physical deconditioning is less clear. A possible explanation is the use of self-reported or cardiorespiratory/aerobic fitness measures to evaluate physical activity (PA) levels. Accelerometers are able to measure physical activity in real time, providing more objectivity regarding frequency, intensity and duration of PA.
Purpose: The aim of this study was to test that fear of movement is associated with PA levels measured by objective and subjective methods and the influence of disability in this association in people with chronic non-specific LBP.
Methods: Patients aged between 18 and 60 years old with non-specific chronic LBP, reporting at least moderate pain and interference with function were eligible for the study. We collected data regarding objective (i.e. time spent on moderate-to-vigorous PA, steps, bouts, counts) and subjective PA levels (i.e. Baecke Physical Activity Questionnaire), fear of movement (i.e. TSK), pain intensity, depression, education level and work status. Patients were instructed to wear an accelerometer during waking hours (except when showering, bathing or swimming) while maintaining their typical weekly schedule for 7 days. The associations between TSK and PA measures were examined separately with correlational and multivariate linear regression analyses with a backward elimination approach.
Results: .A sample of 119 participants mainly female (69%), mean age of 40 (SD= 19) years and median symptom duration of 12 (IQR= 42) months was included. Age, symptoms duration, gender, disability and pain were associated (p≤0.25) with TSK and considered as covariates for the multivariate models. Our analyses revealed that fear of movement is not associated with any objective PA measures. Also, the apparent association between self-reported PA and fear of movement (correlational analyses: r= -0.18; p 0.05; univariate regression analyses: β= -0.04, 95% CI: 0.07 to -0.01, p = 0.04) was not confirmed with disability analyzed as a covariate. Yet, disability was found to be associated with fear of movement even after controlling for potential confounders (β= 0.21; 95% CI: 0.11 to 0.31, p 0.001).
Conclusion(s): Fear of movement is not associated with PA levels or pain in patients with chronic LBP. Nevertheless, our results support the fear-avoidance assumption that higher fear of movement lead to more disability but not necessarily to inactivity Future studies are needed to fully understand the role of fear of movement in the development and persistence of pain-related disability.
Implications: The lack of association was found regardless of the physical activity assessment method used, accelerometry or self-reported questionnaires. One interpretation for this result is that patients having higher fear of movement would avoid spine-related functions, such as those tasks described in the RMDQ, but would remain physically active during their daily routine.
Funding acknowledgements: Supported by the São Paulo Research Foundation (grant nos. 2015/17093-7, 2015/07704-9, 2015/02744-2, and 2014/14077-8).
Topic: Disability & rehabilitation
Ethics approval: This study was approved by the ethics research committee of the Sao Paulo State University (CAAE36332514.0.0000.5402).
All authors, affiliations and abstracts have been published as submitted.
