An investigation into the effects of a posterior-to-anterior lumbar mobilisation technique on neurodynamic mobility in the lower limb

Abstract

Background and Objectives: Spinal mobilisation is commonly used in the field of manual medicine to address lumbar joint dysfunction. In addition, lumbar mobilisation has been proposed as a method to improve lower limb neurodynamic mobility, however, there is no published research to support this hypothesis. The aim of this study was to evaluate the effect of a posterior-to-anterior lumbar mobilisation technique on straight leg raise (SLR) and passive knee extension (PKE).

Methods: A randomised controlled experiment was conducted. Male participants (n=23) were recruited and randomly allocated to receive a posterior-to-anterior L4/L5 lumbar mobilisation or a sham technique. Additional male participants (n=12) were recruited into a control group. The main outcome measures used to represent lower limb range of motion were SLR and PKE tests; neck flexion (NF) was used as a structural differentiation test to reduce neurodynamic mobility for each measure.

Results: The experimental intervention demonstrated a ‘very large’ effect (d=2.14) on increased pre-post SLR measurements and a ‘large’ effect (d=1.6) on SLRNF when compared with the control group. The sham intervention was associated with similar improvements, demonstrating a ‘large‘ effect for both pre-post SLR (d=1.7) and SLRNF (d=1.3) ranges. Analysis between experimental, sham and control groups showed a significant increase for pre-post ranges of SLR (p<0.001) and SLRNF (p=0.003). Pre-post ranges of PKE were not affected by either intervention (p=0.36). Immediate improvements in range of SLR (p<0.01) and SLRNF (p<0.04) following the application of the lumbar mobilisation or sham technique were not evident after a 48-hour follow-up period. The addition of neck flexion as a structural differentiation test demonstrated a ‘trivial’ effect on pre-post ranges of SLR versus SLRNF (d<0.16) for all intervention groups.

Conclusion: A posterior-to-anterior lumbar mobilisation technique applied to the L4/L5 vertebrae improved neurodynamic SLR and SLRNF mobility, with minimal effect on PKE measurements, however, the sham technique demonstrated similar results. A placebo effect is discussed to explain these comparative findings. These observed improvements are not attributable to the engagement of joint articulation applied at a putative neural convergence point in the lumbar spine. The application of the L4/L5 PA lumbar mobilisation and sham technique increased lower limb neurodynamic mobility in asymptomatic male participants.

NB. The results of this research have been published online at sportEX magazine, Background and Objectives: Spinal mobilisation is commonly used in the field of manual medicine to address lumbar joint dysfunction. In addition, lumbar mobilisation has been proposed as a method to improve lower limb neurodynamic mobility, however, there is no published research to support this hypothesis. The aim of this study was to evaluate the effect of a posterior-to-anterior lumbar mobilisation technique on straight leg raise (SLR) and passive knee extension (PKE).

Methods: A randomised controlled experiment was conducted. Male participants (n=23) were recruited and randomly allocated to receive a posterior-to-anterior L4/L5 lumbar mobilisation or a sham technique. Additional male participants (n=12) were recruited into a control group. The main outcome measures used to represent lower limb range of motion were SLR and PKE tests; neck flexion (NF) was used as a structural differentiation test to reduce neurodynamic mobility for each measure.

Results: The experimental intervention demonstrated a ‘very large’ effect (d=2.14) on increased pre-post SLR measurements and a ‘large’ effect (d=1.6) on SLRNF when compared with the control group. The sham intervention was associated with similar improvements, demonstrating a ‘large‘ effect for both pre-post SLR (d=1.7) and SLRNF (d=1.3) ranges. Analysis between experimental, sham and control groups showed a significant increase for pre-post ranges of SLR (p<0.001) and SLRNF (p=0.003). Pre-post ranges of PKE were not affected by either intervention (p=0.36). Immediate improvements in range of SLR (p<0.01) and SLRNF (p<0.04) following the application of the lumbar mobilisation or sham technique were not evident after a 48-hour follow-up period. The addition of neck flexion as a structural differentiation test demonstrated a ‘trivial’ effect on pre-post ranges of SLR versus SLRNF (d<0.16) for all intervention groups.

Conclusion: A posterior-to-anterior lumbar mobilisation technique applied to the L4/L5 vertebrae improved neurodynamic SLR and SLRNF mobility, with minimal effect on PKE measurements, however, the sham technique demonstrated similar results. A placebo effect is discussed to explain these comparative findings. These observed improvements are not attributable to the engagement of joint articulation applied at a putative neural convergence point in the lumbar spine. The application of the L4/L5 PA lumbar mobilisation and sham technique increased lower limb neurodynamic mobility in asymptomatic male participants.

NB. The results of this research have been published online at sportEX magazine, available at http://content.yudu.com/A1rorp/27DY10-14/