Segmental spine mobility differences between lumbar flexion- and extension-based movement syndromes in patients with low back pain

BACKGROUND: The Movement System Impairment (MSI) model is useful for identifying spine-hip mobility and motor control deficits that may contribute to low back pain (LBP). While previous studies have found differences in global spine-hip movement impairments between lumbar MSI subgroups, no studies have compared segmental spine movement impairments between these subgroups. Therefore, the purpose of this study is to analyze segmental lumbar mobility in participants with LBP and a lumbar flexion- or extension-based MSI. METHODS: Forty participants with subacute-chronic LBP were placed into one of three age groups (< 35, 35-54, or > 54 years-old) and then classified into a flexion- or extension-based MSI sub-group. Segmental lumbar range of motion (ROM) was measured in degrees using a skin-surface device. Total lumbar and segmental flexion and extension ROM of L1-L2 to L5-S1 was compared between MSI sub-groups for each age group using separate two-way ANOVAs. RESULTS: Significant main effects were found for the independent variables of MSI subgroup and age. Participants in all three age groups with a flexion-based MSI displayed significantly less lumbar extension (-0.6 degrees) at L4-5 as compared to participants with an extension-based MSI (-2.1 degrees), p = 0.03. In addition, lumbar total and segmental ROM was significantly less for older individuals in both subgroups. CONCLUSIONS: Individuals with LBP may demonstrate a pattern of lumbar segmental hypomobility in the opposite direction of their MSI. Future studies may investigate the added value of direction-specific spinal mobilization to a program of MSI-based exercise.-