Mechanical traction for mechanical neck disorders: a systematic review.

OBJECTIVE: To assess whether mechanical traction, either alone or in combination with other treatments, improves pain, function/disability, patient satisfaction and global perceived effect in adults with mechanical neck disorders. METHODS: We conducted a systematic review up to September 2004 of randomized controlled trials and used pre-defined levels of evidence for qualitative analysis. Two independent reviewers conducted study selection, data abstraction and methodological quality assessment. Using a random effects model, relative risk and standardized mean differences were calculated. The reasonableness of combining studies was assessed on clinical and statistical grounds. In the absence of heterogeneity, pooled effect measures were calculated. RESULTS: Of the 10 selected trials, one study was of high quality. Our review revealed low-quality trials for mechanical neck disorders, showing evidence of benefit favouring intermittent traction for pain reduction. Continuous traction showed no significant difference for defined outcomes. CONCLUSION: Inconclusive evidence for continuous and intermittent traction exists due to trial methodological quality. Two clinical conclusions may be drawn, one favouring the use of intermittent traction and the other not supporting the use of continuous traction. Attention to research design flaws and description of traction characteristics is needed.