Conservative management of mechanical neck disorders. A systematic overview and meta-analysis

This overview reports the efficacy of conservative treatments (drug therapy, manual therapy, patient education, physical medicine modalities) in reducing pain in adults with mechanical neck disorders.

Computerized bibliographic database searches from 1985 to December 1993, information requests from authors, and bibliography screenings were used to identify published and unpublished research. Applying strict criteria, two investigators independently reviewed the blinded articles. Each selected trial was evaluated independently for methodologic quality.

Twenty-four randomized controlled trials (RCTs) and eight before-after studies met our selection criteria. Twenty RCTs rated moderately strong or better in terms of methodologic quality. Five trials using manual therapy in combination with other treatments were clinically similar, were statistically not heterogeneous (p = 0.98), and were combined to yield an effect size of -0.6 (95% CI: -0.9, -0.4), equivalent to a 16 point improvement on a 100 point pain scale. Four RCTs using physical medicine modalities were combined using the inverse chi-square method: two using electromagnetic therapy produced a significant reduction in pain (p < 0.01); and two using laser therapy did not differ significantly from a placebo (p = 0.63). Little or no scientific evidence exists for other therapies, including such commonly used treatments as medication, rest and exercise.

Within the limits of methodologic quality, the best available evidence supports the use of manual therapies in combination with other treatments for short-term relief of neck pain. There is some support for the use of electromagnetic therapy and against the use of laser therapy. In general, other interventions have not been studied in enough detail adequately to assess efficacy or effectiveness. This overview provides the foundation for an evidence-based approach to practice. More robust design and methodology should be used in future research, in particular, the use of valid and reliable outcomes measures.