Electrotherapy for neck pain
Abstract
Background
Neck pain is common, disabling and costly. The effectiveness of electrotherapy as a physiotherapeutic option remains unclear. This update replaces our 2005 Cochrane review on this topic.
Objectives
To assess whether electrotherapy improves pain, disability, patient satisfaction, and global perceived effect in adults with neck pain.
Search methods
Computer‐assisted searches of: CENTRAL, MEDLINE, EMBASE, MANTIS, CINAHL, and ICL, without language restrictions, from their beginning to December 2008; handsearched relevant conference proceedings; consulted content experts.
Selection criteria
Randomised controlled trials in any language, investigating the effects of electrotherapy, used primarily as unimodal treatment for neck pain. Quasi‐RCTs and controlled clinical trials were excluded.
Data collection and analysis
At least two authors independently conducted citation identification, study selection, data abstraction, and risk of bias assessment. We were unable to statistically pool any of the results, but assessed the quality of the evidence using an adapted GRADE approach.
Main results
Eighteen small trials (1043 people with neck pain) with 23 comparisons were included. Analysis was limited by trials of varied quality, heterogeneous treatment subtypes and conflicting results. The main findings for reduction of neck pain by treatment with electrotherapeutic modalities are:
Very low quality evidence that pulsed electromagnetic field therapy (PEMF), repetitive magnetic stimulation (rMS) and transcutaneous electrical nerve stimulation (TENS) are more effective than placebo.
Low quality evidence that permanent magnets (necklace) are not more effective than placebo.
Very low quality evidence that modulated galvanic current, iontophoresis and electric muscle stimulation (EMS) are not more effective than placebo.
There were only four trials that reported on other outcomes such as function and global perceived effects, but none were of clinical importance.
Authors' conclusions
We cannot make any definite statements on the efficacy and clinical usefulness of electrotherapy modalities for neck pain. Since the quality of evidence is low or very low, we are uncertain about the estimate of the effect. Further research is very likely to change both the estimate of effect and our confidence in the results. Current evidence for PEMF, rMS, and TENS shows that these modalities might be more effective than placebo but not other interventions. Funding bias should be considered, especially in PEMF studies. Galvanic current, iontophoresis, electric muscle stimulation(EMS), and static magnetic field did not reduce pain or disability. Future trials on these interventions should have larger patient samples and include more precise standardization and description of all treatment characteristics.
PICOs
Plain language summary
Electrotherapy for neck pain
Neck pain is common, disabling and costly. Electrotherapy is an umbrella term that covers a number of therapies that aim to reduce pain and improve muscle tension and function.
This updated review included 18 small trials (1043 people). The results of the trials could not be pooled because they examined different populations, types and doses of electrotherapy, and comparison treatments and measured slightly different outcomes.
We cannot make any definitive statements about the efficacy of electrotherapy for neck pain because of the low or very low quality of the evidence for each outcome, which in most cases, was based on the results of only one trial.
For patients with acute neck pain, TENS possibly relieved pain better than electrical muscle stimulation, not as well as exercise and infrared and as well as manual therapy and ultrasound. There was no additional benefit when added to infrared, hot packs and exercise, physiotherapy or a combination of a neck collar, exercise and pain medication.
For patients with acute whiplash, iontophoresis was no more effective than no treatment, interferential current or a combination of traction, exercise and massage for relieving neck pain with headache; pulsed electro‐magnetic field was more effective than ‘standard care’.
For patients with chronic neck pain, TENS possibly relieved pain better than placebo and electrical muscle stimulation, not as well as exercise and infrared and possibly as well as manual therapy and ultrasound; pulsed electro‐magnetic field was possibly better than placebo, galvanic current, and electrical muscle stimulation. Magnetic necklaces were no more effective than placebo for relieving pain; there was no additional benefit when electrical muscle stimulation was added to either mobilisation or manipulation.
For patients with myofascial neck pain, TENS, FREMS (variation of TENS) and repetitive magnetic stimulation seemed to relieve pain better than placebo.
While over half of the trials were assessed as having a low risk of bias, seven of them did not describe how their participants were randomised, eight did not conceal the treatment assignment, and 12 did not control co‐interventions. The trials were very small, with a range of 16 to 336 participants. Sparse and imprecise data mean the results cannot be generalized to the broader population and contributes to the reduction in the quality of the evidence, which was low or very low for all results. Therefore, further research is very likely to change the results and our confidence in them.
