Daily physical activities in chronic lower back pain patients assessed with accelerometry M.G.H. van Weering a, * , M.M.R. Vollenbroek-Hutten a , T.M. Tönis a , H.J. Hermens a,b a Roessingh Research and Development, Enschede, The Netherlands b Faculty of Electrical Engineering, Mathematics and Computer Science, University of Twente, Enschede, The Netherlands article info Article history: Received 4 December 2007 Received in revised form 11 June 2008 Accepted 16 July 2008 Available online xxxx Keywords: Daily activities Accelerometry Chronic lower back pain Physical activity level abstract Background: Normalization of activities in daily living is an important goal in rehabilitation treatment of chronic lower back pain (CLBP) patients. Clinicians indicate that CLBP patients often show deconditioning but also CLBP patients who seem to be too active are seen. The objective of the present cross-sectional study was to gain more insight into the daily activity pattern of CLBP patients compared to controls, using accelerometry. Methods: Daily activities were assessed by measuring body movement with a tri-axial accelerometer that was worn for seven consecutive days during waking hours. Measurements were performed in the daily environment (in-doors and out-doors) of the participant. Differences between activity level, time of day and work status were tested. Results: Data were obtained from 29 CLBP patients and 20 controls. Results show that the overall activity levels of patients (mean 0.75; SD 0.43) are not significantly different from those of controls (mean 0.71; SD 0.44). However, patients show significantly higher activity levels in the morning (p < 0.001) and sig- nificantly lower activity levels in the evening (p < 0.01) compared to controls. No significant differences in activity levels were found between leisure time and working days within either group; furthermore no significant differences in activity levels were found between patients with different work status. Conclusion: Overall activity levels do not differ significantly between CLBP patients and controls, but the distribution of activities over the day differs significantly. Ó 2008 European Federation of Chapters of the International Association for the Study of Pain. Published by Elsevier Ltd. All rights reserved. 1. Introduction Chronic lower back pain (CLBP) is an increasingly important health problem. Picavet and Hazes (2003) showed that 27% of the Dutch population suffers from lower back pain. In most sub- jects these symptoms disappear quickly, in less than six weeks. In a small group of patients with lower back pain (10%), complaints are not resolved within six weeks and these patients might develop CLBP. Yet this small group of CLBP subjects account for up to 90% of all medical and societal costs for LBP (Nachemson, 1992). The management of lower back pain is difficult because of insufficient knowledge about the causes of CLBP and the mecha- nisms by which pain is developed and maintained. As a result, a multidimensional approach of CLBP has now been widely recog- nized and a variety of multidisciplinary treatments have been developed. For years, enhancement of a patient’s level of physical fitness and normalization of activities of daily living has been an important goal in rehabilitation treatment in CLBP, merely based on the hypothesis that physical deconditioning contributes to the chronification of lower back pain (Vlaeyen et al., 1995). However, clinicians indicate that not every patient with CLBP seen in clinical practice shows a deconditioning and that there are apparently some patients who are (too) active. In addition to the clinical observations, a recent review on daily activities of patients with chronic pain and/or fatigue showed that for CLBP the results were inconclusive (van Weering et al., 2007). Of the twelve studies in- cluded in this review, two described CLBP. One study showed a similar physical activity level in patients with CLBP over the whole day compared to a control group (Verbunt et al., 2001). The other study showed a similar activity level during the day, but a lowered activity level during the evening in patients with CLBP compared to controls (Spenkelink et al., 2002). Another more recent study, which was not yet published at the time of the review, showed a lower intensity of everyday physical activity in patients with lower back pain compared to controls (van den Berg-Emons et al., 2007). Based on these results, it can be concluded that more insight into differences in activity patterns over the day between patients and controls is needed. All three studies hypothesize that work sta- tus of patients might be an explanatory factor for the differences 1090-3801/$34.00 Ó 2008 European Federation of Chapters of the International Association for the Study of Pain. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ejpain.2008.07.005 * Corresponding author. Tel.: +31 (0) 53 4875764; fax +31 (0) 53 4340849. E-mail address: m.vanweering@rrd.nl (M.G.H. van Weering). European Journal of Pain xxx (2008) xxx–xxx Contents lists available at ScienceDirect European Journal of Pain journal homepage: www.EuropeanJournalPain.com ARTICLE IN PRESS Please cite this article in press as: van Weering MGH et al., Daily physical activities in chronic lower back pain patients assessed ..., Eur J Pain (2008), doi:10.1016/j.ejpain.2008.07.005