Evidence-based therapeutic ultrasound can be administered at any stage throughout the healing process (inflammation, proliferation and remodelling phases), including most chronic inflammatory conditions. The main objective of therapeutic ultrasound is to enhance the natural healing process of tissue repair. For optimum clinical effect, ultrasound should not be used in isolation, but ideally, used to compliment other treatment modalities, particularly massage and other manual therapy techniques.

Therapeutic ultrasound is preferentially absorbed by high-protein, dense collagenous tissues. This has great significance in the clinical setting for the treatment of ligaments, tendon, fascia, joint capsule, and scar tissue (1,2,3,4). According to Watson (4), the therapeutic effectiveness of any treatment (i.e. manual therapy or electrotherapy) is both ‘modality’ and ‘dose’ sensitive - and therefore represent key issues. Furthermore, treatment settings (e.g. dose, intensity, pulse ratio, treatment duration) are based on the clinical findings of the patients’ condition (e.g. acute, sub-acute and chronic). Where, it is generally accepted that all forms of treatment and rehabilitation should be based on sound scientific principles underlying tissue healing (5,6). Therefore, it is crucial that the therapist has an understanding of the various stages of the healing process, and the clinical implications of a perpetuating inflammatory cycle.

While ultrasound is recognised for physiological effects, it can also have a significant psychological placebo effect (7,8). Subsequently, it is purported that correct evidence-based settings can provide a combined optimum effect, physiologically and psychologically.

What the Research tells us:

In reviewing the current research literature relating to the use of ultrasound for the treatment of musculoskeletal conditions, many systematic reviews have failed to support the efficacy of its continued use (9,10,11,12,13). However, supporting its continued use, Watson (14) reports that many studies lack accurate data on clinical settings, while, Robertson et al. (3) reports many studies lack evidence of equipment calibration. Furthermore, even many authors of these systematic reviews report the quality of studies are often poor, and further efforts are necessary to provide stronger evidence.

Conclusion:

Far too often therapeutic ultrasound gets dismissed owing to the lack of robust evidence. Yet, it remains one of the most widely used and accepted electrotherapy modalities in Europe. Frustratingly, there is more evidence to support ultrasound than many of the manual therapy techniques that are widely used.  Absence of evidence does not always mean that there is evidence of absence (15). If one looks critically at the full range of physiotherapy treatments, there is simply insufficient evidence to support or reject many of them in all known circumstances (15). Finally, if evidence-based settings are applied in line with the sound scientific principles of tissue healing, the therapist can be reasonably assured of providing evidence-based-practice, capable of delivering safe clinical effective electrotherapy treatments.

References / Sources:

1. Nussbaum, E. (1997). Ultrasound: to heat or not to heat-that is the question. Physical Therapy Review, 2, 59-72.

2. Sparrow, K.J., Finucane, S.D., Owen, J.R., Wayne, J.S. (2004). The effects of low-intensity ultrasound on medial collateral ligament healing in the rabbit model. The American Journal of Sports Medicine. 33 (7), 1048-1055.

3. Robertson, V., Ward, A., Low, J., Reed, A. (2006).  Electrotherapy explained: Principles and practice. Fourth edition. Edinburgh: Butterworth-Heinemann.

4. Watson, T. (2006). Electrotherapy and tissue repair. Journal of  Sportex Medicine, 29, 7-13.

5. Glasgow, P. (2007). Sports rehabilitation: principles and practice. Journal of Sportex Medicine. 32, 10-16.

6. Kannus, P., Parkkari, T.L., Jarvinen, T., et al. (2003). Basic science and clinical studies coincide: active treatment approach is needed after a sports injury. Scandinavian Journal of Medicine and Science in Sports. 13, 150-154.

7. Dyson, M. (1987). Mechanisms involved in therapeutic ultrasound. Physiotherapy, 73(3), 116-120.

8. Kitchen, S.S., Partridge, C.J. (1990). A review of therapeutic ultrasound. Physiotherapy, 76(10), 593-600.

9. Gam, A.N., Johannsen, F. (1995). Ultrasound therapy in musculoskeletal disorders: a meta-analysis. Pain, 63, 85-91.

10. Ogilvie-Harris, D.J., Gilbart, M. (1995). Treatment modalities for soft tissue injuries of the ankle: a critical review. Clinical Journal of Sport Medicine, 5(3), 175-186.

11. Van der Heijden, G.J.M., Van der Windt, D.A.W., De Winter, A.F. (1997). Physiotherapy for patients with soft tissue shoulder disorders: A systematic review of randomised clinical trials. British Medical Journal, 315(7099), 25-30.

12. Van der Windt, D.A., Van der Heijden, G.J., Van der Berg, S.G., Ter Riet, G., de Winter, A.F., Bouter, L.M. (1999). Ultrasound therapy for musculoskeletal disorders: a systematic review. Pain, 81(3), 257-271.

13. Van der Windt, D.A.W.N., Van der Heijden, G.J.M.G., Van den Berg, S.G.M., Ter Riet, G., De Winter, A.F., Bouter, L.M. (2002). Therapeutic ultrasound for acute ankle sprains. Cochrane Database of Systematic Reviews 2002. Issue 1. Art. No.: CD001250. DOI: 10.1002/14651858. CD001250.

14. Watson, T. (2005). Current concepts in electrotherapy. Theoretical & practical ultrasound workshop literature. University of Hertfordshire, Oct. 2005.

15. Watson, T. (2000). The role of electrotherapy in contemporary physiotherapy practice.  Manual Therapy, 5, 132-141.

Information source: Electrotherapy on the Web: an educational source by Professor Watson. http://www.electrotherapy.org/

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