Motorised lumbar traction in the management of low back pain with nerve root involvement: A feasibility study of effectiveness

PURPOSE: Nerve root involvement accompanies between 3-10% of Low Back Pain (LBP) and despite current guidelines, lumbar traction is a treatment still used by 40% of physiotherapists treating such patients. However its benefits remain to be established. The aim of this study was to establish the feasibility of a pragmatic Randomized Controlled Trial (RCT) to compare two treatment protocols reflecting current clinical practice (manual therapy, exercise and advice, with or without traction) in the management of acute/sub acute low back pain with ‘nerve root’ involvement. RELEVANCE: Evidence for the effectiveness of lumbar traction remains inconclusive due to the poor methodological quality, inadequate treatment doses, and heterogeneous populations used in past studies. This study addressed these issues by investigating a homogeneous group (‘nerve root’) and used treatment parameters for traction established from a UK wide survey of current practice. This represents the first high quality trial reflecting current traction use. PARTICIPANTS: 30 patients with nerve root pain, with or without neurological signs, were recruited between March 2004 and February 2005 within Down Lisburn Health and Social Care Trust, Northern Ireland. METHODS: A pragmatic RCT design was employed with patients randomly assigned to one of two treatment groups: Manual therapy (manual therapy, exercises and the ‘Back Book’) or Lumbar traction (lumbar traction, manual therapy, exercises and the ‘Back Book’). Outcome measures used were the: McGill pain questionnaire, Roland Morris disability questionnaire, Short form 36, and the Acute LBP Screening Questionnaire; these were recorded at baseline, discharge, 3 and 6 months post-discharge. In addition, visual analogue scale (VAS) scores for back and leg pain, the percentage of overall improvement (patient’s perception), and changes in neurological and neurodynamic tests were recorded. ANALYSIS: Data recorded from the primary outcome measures, VAS scores and percentage overall improvement were considered interval level and analysed with parametric statistics: repeated measures ANOVA (within group changes) and the independent t-test (between group changes). RESULTS: 27 patients completed treatment with a loss of four patients at the 3 and 6 month follow up: data for 23 patients were analysed. ANOVA showed a significant improvement in pain and disability from baseline to all follow up points for both groups; however there was no significant difference between groups. Feasibility issues highlighted that recruitment, selection, and outcome measures were appropriate however a sample size calculation suggested that a large study would be unfeasible (n=1,975). CONCLUSIONS: The results demonstrated that both groups improved with treatment but that no additional benefit was achieved with the addition of lumbar traction to the package of care. IMPLICATIONS: This study demonstrates that a study with this subgroup of LBP is feasible; however in light of the sample size calculation some aspects of the design would need to be reconsidered prior to a fully powered pragmatic RCT