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Electrotherapy: evidence-based practice (12th edition)
  1. David Mayor
  1. Correspondence to Mr David Mayor, 86 Handside Lane, Welwyn Garden City AL8 6SJ, UK; davidmayor{at}welwynacupuncture.co.uk

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Tim Watson. Published by Churchill Livingstone, Edinburgh 2008 £41.99 978-0-443-10179-3

Edward B Clayton’s Electrotherapy and actinotherapy was first published by Baillière, Tindall and Cox in 1949, an amalgamation of Electrotherapy with the direct and low frequency currents (1944) and Actinotherapy and diathermy for the student (1939). It still bore the title Clayton’s electrotherapy in its 10th edition, edited by Sheila Kitchen and Sarah Bazin (Saunders, 1996). In the meantime, though, the fashionable catchphrases “evidence-based” and “evidence-based medicine” had been introduced (in 1990 and 1996, respectively), and the book’s next incarnation was revamped to its current title, with Kitchen as sole editor. The current edition has again been edited single-handedly, by Tim Watson, Professor of Physiotherapy at the University of Hertfordshire, and was published in 2008 by Elsevier under the Churchill Livingstone imprint. Associated material can be accessed (and downloaded) by purchasers at http://evolve.elsevier.com/productPages/s_1451.html (accessed 12 May 2009). Further useful information is available at Watson’s own website, Electrotherapy on the web, at http://www.electrotherapy.org/ (accessed 12 May 2009).

Watson’s emphasis throughout, as shown in his own thorough and well constructed contributions to this volume, is on evidence-based practice as an integration of “individual clinical expertise with the best available external clinical evidence from systematic research” (p vii). Not all his co-contributors have been so careful, however, and there is still room for improvement if the book’s contents are to conform consistently with its title.

The book contains 21 chapters in five section: (1) Introduction and scientific concepts (8 chapters); (2) Thermal and non-thermal modalities (4 chapters); (3) Electrical stimulation modalities (7 chapters); (4) Ultrasound imaging (1 chapter); and (5) Contraindications, dangers and precautions (1 chapter, “Guidance for the clinical use of electrophysical agents”, published in 2006 by the Chartered Society of Physiotherapists). Comparison with my battered and much read copy of the 10th edition (I have not seen the 11th) gives some surprising results:

In Section 1, for example, many of the chapters have been little changed, apart from excluding some historical accounts of the development of particular modalities, re-ordering bits and pieces within chapters or sections, updating references and illustrations (the latter mostly through a judicious use of colour rather than anything else) and in some cases altering author attributions. Here only one chapter (ch. 6, “Physiology of pain”, by Leslie Wood) is significantly different from the same contributor’s earlier version (referencing in both is disappointing). Thus it would seem that the scientific underpinnings of electrotherapy have not altered that much within the last 12 years or so, despite a clear acceleration of change in many other areas of scientific research.

In Section 2, on the other hand, apart from the complete omission of two chapters on the currently unfashionable modalities of microwave diathermy and ultraviolet, there are also considerable changes and improvements in Sheila Kitchen’s chapter on “Heat and cold application” (which already, back in 1996, included a brief disquisition on “evidence for clinical efficacy”), a much improved presentation on “Pulsed and continuous shortwave therapy” by Maryam Al-Mandeel and Tim Watson, and a very informative chapter on “Therapeutic ultrasound” by Watson and Stephen Young. These last two chapters contain a wealth of new evidence for efficacy, whereas “Low-intensity laser therapy” by David Baxter, the other chapter in this section, is relatively little changed, apart from more precise indications on the power and energy per point that should be used for best results. Curiously, Baxter no longer includes references to Semion Rochkind’s research on tissue repair.

Section 3, in many ways of most relevance to acupuncturists, starts with a completely rewritten “Introduction to low-frequency currents” by Deirdre Walsh, based solely on up-to-date references, followed by a rather technical chapter on “Neuromuscular electrical stimulation” by Mary Cramp and Oona Scott (with much new material, but only a page on clinical studies—on Bell’s palsy, rheumatoid arthritis, chronic heart failure and Duchenne muscular dystrophy). This is followed by a more clinically oriented “how-to” chapter on “Neuromuscular and muscular electrical stimulation” by Suzanne McDonough, with a good evidence base (although it only consists of a relatively small number of studies). After this comes the longest and most ambitious chapter in the book, Mark Johnson’s contribution on TENS. His approach is comprehensive and critical (sometimes perhaps overly judgmental), based on a wealth of recent research studies, both experimental and clinical. He even briefly mentions various “TENS-like devices”, such as Alex Macdonald’s transcutaneous spinal electroanalgesia and handheld piezoelectrical stimulators such as the PainGone device.

While acknowledging that some opinion leaders define acupuncture-like TENS (AL-TENS, or low frequency, high amplitude TENS), without reference to muscle contractions, and that many research reports also do not mention motor effects, Johnson characterises it as “the induction of forceful but non-painful phasic muscle contractions at myotomes related to the origin of the pain” (p262). He thus feels justified in explaining—somewhat dogmatically—that AL-TENS operates by selective activation of Aα (Group I) efferents (mistyped as Aδ), resulting in activity in ergo-receptors and Group III (Aδ) afferents, as opposed to “intense TENS” (high frequency, high intensity TENS) that activates Aδ fibres directly. In both cases, Aδ activation leads to extrasegmental analgesia, and the concomitant Aβ afferent activation to segmental analgesia. As he says, “there is a lack of good-quality and systematic experimental work that has directly compared the clinical effectiveness and analgesic profiles of these types of TENS” (p263)—perhaps because, in essence, there is not a huge difference between them in terms of final common neurological pathways.

Chapter 17, by Shea Palmer and Denis Martin, is a complete rewrite of the latter’s earlier version of the chapter on “Interferential current” (IFC), taking theoretical, laboratory and clinical evidence into account. As its authors conclude, “it is still not clear whether IFC is, indeed, efficacious or which aspects of clinical conditions are affected. There is also the key question of whether IFC is any more effective than other, more accessible, forms of electrical stimulation such as TENS” (p311). As in so many forms of physiotherapy, the attempt to squeeze positive results from research is laborious and still all too often quite unproductive.

The next chapter, “Functional electrical stimulation” (by David Ewins and Sally Durham), covering the application of electrical impulses to the body to restore lost or impaired functions, is less relevant to those practising acupuncture than Watson’s final chapter in this section (“Electrical stimulation for enhanced wound healing”), and more an account of methods used than of the evidence for their usefulness. Watson’s chapter, on the other hand, like his other contributions to this volume, is very much evidence-based. Yet, as he comments, despite the drive towards evidence-based practice, and “although there have been many publications in this research area, especially in more recent years, there appears to be a reluctance to use the therapy in the clinical environment” (p329).

The single chapter in Section 4 (“Musculoskeletal ultrasound imaging”), by John Leddy, is disappointingly not particularly evidence-based, and does not fit easily with the rest of the book. In part this is because “the use of ultrasound imaging in physiotherapy is still in its infancy” (p349), in part because this chapter was not included in previous editions of the book, in part because it is about a method of evaluating and monitoring change rather than about actual treatment.

The final chapter, which covers much more than the title of Section 5 would suggest, will be essential reading for all those practitioners whose patients receive electrotherapy, whether from themselves or elsewhere.

In conclusion, this book is both comprehensive and an extremely useful summary of current knowledge in electrotherapy that will be of use to all clinicians whose patients have undergone (or are currently receiving) such treatment or who wish to clarify whether referral for electrotherapy might be appropriate. It will be of particular interest to acupuncture practitioners, whose interventions often overlap with those of physical therapy, both theoretically and in effect. For those who use electrotherapeutic acupoint-based modalities such as electroacupuncture, TEAS (transcutaneous electrical acupoint stimulation)/TENS, laser acupuncture or far infrared (“TDP”) lamps, this will be a key book, offering a thoroughly grounded Western context for their treatment as well as an Oriental one.

Two limitations of the book are (1) that the quality of evidence used is, for the most part, inadequately analysed (except by Johnson in his chapter on TENS), and (2) that the studies cited are virtually all from English-language publications, despite the fact that research in some areas is mostly not available in English. To remedy these defects will take some hard work, which could profitably be taken on board for the next edition. (Hopefully some of the errors in cross-referencing chapters and boxes will also be corrected, along with several instances of “mA” for “μA” in Watson’s chapter on wound healing.)

It is salutary that the conclusions on TENS and IFC quoted above are echoed repeatedly throughout this volume. The authors of the chapter on shortwave therapy, for example, writing about differences between pulsed shortwave and pulsed electromagnetic fields, conclude that “Demonstration of the similarity or difference between these modes is an important issue in the next generation of research in this field” (p156). The chapter on neuromuscular electrical stimulation concludes that “There is still uncertainty over optimum patterns of electrical stimulation in different physiological circumstances” (p226). On wound healing, Watson writes of direct current (DC), pulsed DC and alternating current (AC) modes, that “Differentiation between these modes of intervention is currently problematic”, although all appear to “have a clinically significant effect” (p344). As McDonough concludes her chapter, “as with many other electrophysiological agents, there are still major gaps in our knowledge about the effects of electrical stimulation, the most effective parameters for its use and its long-term efficacy” (p209). A similar concern with parameters and what Tim Watson terms “treatment dose” in the context of the whole “package of care” is, of course, evident in the literature of acupuncture and its many variants as well (see Adrian White’s editorial in the June 2008 issue of Acupuncture in Medicine). Knowledge is never complete, much research remains to be done, and this book provides a useful overview of a field that is developing in many ways parallel to our own. Those working in both fields will learn much from each other in the future.

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Footnotes

  • Competing interests Tim Watson is academic supervisor for the reviewer's project to update the electroacupuncture clinical studies database now available at http://www.electroacupunctureknowledge.com/.

  • Provenance and peer review Not commissioned; not externally peer reviewed.

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