Low back pain and postural sway during quiet standing with and without sensory manipulation: a systematic review

A previous review concluded that postural sway is increased in patients with low back pain (LBP). However, more detailed analysis of the literature shows that postural deficit may be dependent on experimental conditions in which patients with LBP have been assessed. The research question to be answered in this review was: "Is there any difference in postural sway between subjects with and without LBP across several sensory manipulation conditions?". A literature search in Pubmed, Scopus, Embase and PsychInfo was performed followed by hand search and contact with authors. Studies investigating postural sway during bipedal stance without applying external forces in patients with specific and non-specific LBP compared to healthy controls were included. Twenty three articles fulfilled the eligibility criteria. Most studies reported an increased postural sway in LBP, or no effect of LBP on postural sway. In a minority of studies, a decreased sway was found in LBP patients. There were no systematic differences between studies finding an effect and those reporting no effect of LBP. The proportion of studies finding between-group differences did not increase with increased complexity of sensory manipulations. Potential factors that may have caused inconsistencies in the literature are discussed in this systematic review.