The deconditioning paradigm for chronic low back pain unmasked?

For decades, the deconditioning process has been held responsible for the development and persistence of low back pain associated disability. It was hypothesized that, due to chronic low back pain (CLBP), patients diminish normal activities (also called disuse) and develop, besides societal and emotional problems, physical deconditioning signs such as loss of muscle strength and endurance as well as reduced aerobic capacity (Mayer and Gatchel, 1988; Verbunt et al., 2003). These physical consequences were thought to result in higher vulnerability and, eventually, more pain. Many health care providers adhere to this deconditioning paradigm when choosing physical training elements to improve physical fitness and performance in patients with CLBP (Jette and Jette, 1996; Daykin and Richardson, 2004). No convincing proof, however, for this physical deconditioning theory exists (Smeets et al., 2006a). Cross-sectional studies only have examined loss of aerobic capacity due to persistent pain, with contradictory results. Studies on loss of muscle strength or endurance of low back muscles have been similarly inconclusive. We therefore definitely need more, and especially longitudinal studies, to enlarge our knowledge on this topic. In this issue of Pain, Bousema et al., 2007, report the results of a very appealing longitudinal study of patients measured at 4–7 weeks after onset of back pain and 1 year later. To our knowledge, this is the first paper in which patients with sub-acute low back pain have been followed over the course of a year to determine if deconditioning is indeed a result of chronic pain. The authors should be lauded for their innovative attempt to increase our insight into the development of physical deconditioning and especially, into the change of the total activity level. Bousema et al. assessed indicators of physical deconditioning: body mass, body fat and muscle strength. The level of physical activity in the preceding year (h-PAL), and the perceived physical activity decline since the onset of back pain (PAD) were assessed by questionnaires. A triaxial accelerometer was used to calculate the amount of real life activity during 7