Research Review by Dr. Shawn Thistle©

Date:

July 2008

Study Title:

Evidence-informed management of chronic low back pain with transcutaneous electrical nerve stimulation, interferential current, electrical muscle stimulation, ultrasound, and thermotherapy

Authors:

Poitras S & Brosseau L

Authors’ Affiliations:

Department of Epidemiology and Biostatistics, McGill University, Canada; Physiotherapy Program, Dept. of Rehabilitation Sciences, University of Ottawa, Canada

Publication Information:

The Spine Journal 2008; 8: 226-233.

Summary:

Chronic low back pain (CLBP) remains a challenging condition to manage, one that carries a significant socioeconomic burden. In order to better understand the state of existing literature on non-surgical treatments for CLBP, the North American Spine Society sponsored a special focus issue of The Spine Journal. This review of modalities was one of the papers featured in this issue.

Many manual medicine providers utilize electro-modalities in their practices. Most of these devices deliver some type of electrical input to tissue with the goal of reducing inflammation and swelling, controlling pain, modulating muscle activity, increasing or maintaining strength, and/or enhancing healing. Unfortunately, there is a dearth of evidence to support their efficacy, particularly for chronic LBP. The state of the literature for each modality as it pertains to CLBP will be summarized below. Some may be surprised by the lack of research on these commonly used devices for CLBP, a condition commonly treated in most chiropractic offices.

Transcutaneous Electrical Nerve Stimulation (TENS) – 6 RCTs and a Cochrane Review:
  • a Cochrane Collaboration Review (reference below) concluded that there are too few studies on which to base recommendations
  • 6 other RCT identified: number of treatments utilized and specific TENS parameters varied
  • all 6 studies included a control group (mostly sham TENS) and utilized low frequency/acupuncture or high frequency
  • 2 trials showed a significant pain reduction immediately following TENS treatment (high frequency)
  • contradictory findings were noted in the other 4 studies in post-intervention period assessment
  • for low frequency TENS: pooled results indicate a clinically important improvement (without statistical significance) in pain intensity
  • short-term follow-ups seem to demonstrate more benefit than long-term follow-ups
Interferential Current – no eligible studies found.
Electrical Muscle Stimulation – no eligible studies found.
Ultrasound – no eligible studies found.
Hot/Cold/Ice Packs (Thermotherapy) – no eligible studies found.

Conclusions & Practical Application:

Although electromodalities are commonly used to treat CLBP, there is an alarming lack of evidence to support their use. Even the studies on TENS were generally of poor quality, (with 4 of 6 scoring < 2 on the commonly used Jadad Scale). Generally, high and low-frequency TENS seems to have an immediate impact on pain intensity (particularly high frequency), health status, and even acetaminophen use, but all of these findings come from only one study.

It should be noted that these results are tenuous at best, and TENS appears to have no effect on long-term pain, or perceived disability. It should also be noted that in both studies, results should be considered immediate, and not even short-term by traditional definitions. The results suggest that at best, TENS should be used as an adjunct in short-term treatment plans.

For the other modalities, the dearth of quality (or any!) research on their effectiveness for CLBP should suggest that clinicians utilize alternative treatment approaches.

Additional Reference:

  1. Khadilkar A et al. Cutaneous electrical nerve stimulation (TENS) for chronic low back pain. Cochrane Database Syst Rev. 2005; 20. CD003008.