Physical functioning of low back pain patients: Perceived physical functioning and functional capacity, but not physical activity is affected

Purpose: Physical functioning is a multidimensional construct covering perceived functioning, functional capacity and actual physical activity. Currently, the assessment of physical functioning in low back pain (LBP) patients has been limited to only one or two of these aspects. This study evaluates physical functioning of LBP patients by assessing the three individual aspects using questionnaires and ambulant sensor-based measurements. Methods: Actual physical activity, functional capacity and perceived functioning were measured in 26 patients undergoing patient specific treatment before, direct and 3-4 weeks after the first treatment using, respectively, sensor-based activity monitoring, sensor-based motion analysis test and the Oswestry questionnaire. Patients were compared to a healthy control group. Results: Perceived functioning and functional capacity, but not actual physical activity is impaired in pre-treatment LBP patients. After treatment, patients improved in perceived physical functioning and functional capacity approaching healthy levels, however only slight (p > 0.05) improvements in actual physical activity were found. Moreover, only few and weak correlations were found between the different aspects of physical functioning. Conclusion: Perceived functioning, actual physical activity and functional capacity are three independent outcome dimensions, being complementary but not redundant. Especially, perceived functioning and physical capacity need attention when evaluating LBP patients during rehabilitation.Implications for RehabilitationPerceived physical functioning and physical capacity are negatively affected by low back pain and improve after treatment.Low back pain patients perform their daily activity independent of pain and complaints.Inertia sensor-based motion analysis can objectify treatment effects showing low back pain patients their progress in rehabilitation.New interventions can be justified with inertia sensor technology in low back pain patients.