Assessing Physical Activity in Low Back Pain Patients After Inpatient Rehabilitation: A Comparison of a Direct Versus a Self-report Measure

Purpose: Aim of the present study was to determine the closeness of agreement between self-reported physical activity and an objective measure of physical activity in patients with low back pain. Materials and Methods: 27 subjects with LBP wore an accelerometer (Actigraph GT3X+) for 7 consecutive days and answered a questionnaire on physical activity (GPAQ) over the same period of time. Spearman's correlation and Bland-Alt-man analysis for the agreement between measures for moderate and vigorous intensity as well as for sedentary behavior were calculated. Results: There were weak no-significant correlations between subjective and objective results. Self-reported data showed an overestimation of 46 min/day (vigorous intensity) to 78 min/day (moderate intensity). Sedentary time was underestimated 249 min/day. Discussion: The present results go in line with similar studies that focus different populations. Conclusions: As the self-reported physical activity can be a decisive factor in altering the level of physical activity it should be focused in the development and evaluation of measures promoting physical activity.