title: Effects of lower limb neurodynamic mobilization on intraneural fluid dispersion of the fourth lumbar nerve root: an unembalmed cadaveric investigation.
abstract: OBJECTIVE
  Manual and physical therapists incorporate neurodynamic mobilisation (NDM) to improve function and decrease pain. Little is known about the mechanisms by which these interventions affect neural tissue. The objective of this research was to assess the effects of repetitive straight leg raise (SLR) NDM on the fluid dynamics within the fourth lumbar nerve root in unembalmed cadavers.
  
  
  METHODS
  A biomimetic solution (Toluidine Blue Stock 1% and Plasma) was injected intraneurally, deep to the epineurium, into the L4 nerve roots of seven unembalmed cadavers. The initial dye spread was allowed to stabilise and measured with a digital calliper. Once the initial longitudinal dye spread stabilised, an intervention strategy (repetitive SLR) was applied incorporating NDMs (stretch/relax cycles) at a rate of 30 repetitions per minute for 5 minutes. Post-intervention calliper measurements of the longitudinal dye spread were measured.
  
  
  RESULTS
  The mean experimental posttest longitudinal dye spread measurement (1.1 ± 0.9 mm) was significantly greater (P = 0.02) than the initial stabilised pretest longitudinal dye spread measurement. Increases ranged from 0.0 to 2.6 mm and represented an average of 7.9% and up to an 18.1% increase in longitudinal dye spread.
  
  
  CONCLUSIONS
  Passive NDM in the form of repetitive SLR induced a significant increase in longitudinal fluid dispersion in the L4 nerve root of human cadaveric specimen. Lower limb NDM may be beneficial in promoting nerve function by limiting or altering intraneural fluid accumulation within the nerve root, thus preventing the adverse effects of intraneural oedema.
authors.affiliation: Center for Rehabilitation Research and Department of Rehabilitation Sciences, School of Allied Health Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
authors.forename: Kerry K
authors.initials: KK
authors.lastname: Gilbert
authors.affiliation: Anatomical Simulation and Research, Patient Safety, and Competency Center, Albany Medical College, Albany, New York, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Smith
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis (LABO), Faculty of Medecine, Université Libre de Bruxelles (ULB), Bruxelles, Belgium.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Sobczak
authors.affiliation: Center for Rehabilitation Research and Department of Rehabilitation Sciences, School of Allied Health Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
authors.forename: C Roger
authors.initials: CR
authors.lastname: James
authors.affiliation: Center for Rehabilitation Research and Department of Rehabilitation Sciences, School of Allied Health Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Sizer
authors.affiliation: Center for Rehabilitation Research and Department of Rehabilitation Sciences, School of Allied Health Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Brismée
keywords: Intraneural oedema; Lumbar; Nerve injury; Nerve root; Neuropathic pain