Revisiting the lumbosacral orthosis from the perspective of dynamical systems theory: a preliminary randomized clinical trial on patients with chronic low back pain.

BACKGROUND The prevalent method for investigating the effect of therapeutic interventions on walking in the individuals with chronic low back pain (CLBP) is component-level approach in which all measurements focus on the spine component alone. However, this approach cannot disclose information about the overall function of the movement system such as complex walking patterns, which, in turn, reveal the underlying movement control. OBJECTIVES To compare the effect of 3-week wearing of lumbosacral orthosis (LSO) along with routine physical therapy with routine physical therapy alone on walking complexity in the individuals with nonspecific CLBP on the basis of the systems approach. STUDY DESIGN Preliminary randomized clinical trial. METHODS Twenty-four subjects were randomly allocated to two groups. The control group received the routine physical therapy for 3 weeks. The intervention group received the same program plus an LSO. Nonlinear analysis was used to quantify walking complexity, as behavior of the entire movement system, before and after the intervention and at 1-month follow-up. RESULTS An average of 496 strides during ten minutes of walking was used for analysis. There was no significant difference (p > 0.05) in degree of walking complexity between two groups during all evaluation periods. CONCLUSIONS The administered orthotic intervention did not alter walking complexity. This suggests that therapeutic goal of current LSOs, which is not based on the systems approach, cannot recover the emergent behavior of the movement system. This may be a potential source of controversies. CLINICAL RELEVANCE To achieve an effective treatment, orthotists should focus on the individuals themselves, not only on their CLBP symptoms. Although the component-level approach aims to decrease the symptoms, the systems approach focuses on the whole context that fosters LBP symptoms.