Fear of Movement Is Not Associated With Objective and Subjective Physical Activity Levels in Chronic Nonspecific Low Back Pain.

OBJECTIVES

To assess the association of physical activity measures, derived with an accelerometer and a self-reported questionnaire, with fear of movement in patients with chronic nonspecific low back pain (LBP) and to investigate the association between disability and fear of movement in this population.

DESIGN

Cross-sectional study.

SETTING

Outpatient physical therapy university clinics.

PARTICIPANTS

Patients (N=119) presenting with nonspecific LBP of >3 months' duration.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Physical activity levels measured objectively with an accelerometer (ie, counts per minute, time spent in moderate-to-vigorous and light physical activity per day, number of steps per day, and number of 10-minute bouts of moderate-to-vigorous physical activity per day) and subjectively with a self-reported questionnaire (Baecke Physical Activity Questionnaire); fear of movement (Tampa Scale of Kinesiophobia); pain (11-point numerical rating scale); disability (Roland Morris Disability Questionnaire); and depression (Beck Depression Inventory). The associations were examined with correlational, univariate, and multivariable linear regression analyses.

RESULTS

None of the objective physical activity measures were associated with fear of movement. The apparent association of self-reported physical activity levels with fear of movement (correlational analyses: r=-.18; P<.05; univariate regression analyses: β=-.04; 95% confidence interval [CI], -.07 to -.01; P=.04) was not confirmed in multivariable analyses. Fear of movement was consistently associated with disability in both correlational (r=.42; P<.01) and multivariable (β=.21; 95% CI, .11-.31; P<.001) analyses.

CONCLUSIONS

Our data support one aspect of the fear-avoidance model-that higher fear of movement is associated with more disability-but not the aspect of the model linking fear of movement with inactivity.