An investigation into the effects of applying a lumbar Maitland mobilisation at different frequencies on sympathetic nervous system activity levels in the lower limb

Background Oscillatory Maitland mobilisations are commonly used in the management of lower back pain with research suggesting that mobilisations at 2Hz may excite the sympathetic nervous system (SNS) more than sustained pressure glides or 0.5Hz oscillatory mobilisations. OBJECTIVES Investigate the effects of increasing the oscillation frequency greater than 2Hz. DESIGN: A double-blind, placebo-controlled, independent group experimental design. Method Sixty healthy male volunteers were randomly allocated to one of four groups; A control group (no contact), placebo group (sustained static pressure to L4 vertebra), and two intervention groups receiving a centrally applied postero-anterior mobilisation applied at either 2Hz or 3Hz for three 1-minute periods. SNS activity was recorded by a blinded data collector by continuous skin conductance (SC) activity levels in the feet using a Biopac MP35 electrodermal amplifier. Participants were blinded to their group allocation which was further validated by a post-experiment questionnaire (p>0.05). Results The magnitude of sympathoexcitatory response was greatest for the 3Hz mobilisation (20%) compared with the 2Hz mobilisation (12%), placebo (-1%) and control conditions (3%). Only the 3Hz group demonstrated statistical significance when compared to placebo intervention (p=0.002), and the control group (p=0.02). Conclusion SC changes reflect those of previous studies using lumbar mobilisations at 2Hz, however the 3Hz group was found to have a greater magnitude of effect worthy of consideration within research and clinical settings. These findings provide preliminary evidence to support the use of 3Hz oscillatory mobilisations to affect a greater magnitude of SNS activity than those previously reported (0.5, 1.5 and 2Hz).