EXTRACORPOREAL SHOCKWAVE THERAPY PARAMETERS FOR MYOFASCIAL TRIGGER POINTS: A NARRATIVE REVIEW

P. Rentzias¹, C. Karagiannis¹, G. Ploutarchou¹, A.Z. Cheimonidou¹

Background: Myofascial trigger points is a common musculoskeletal disorder that is characterized by hyperirritable palpable spots in a muscles’ belly. They may appear in a significant proportion of a population. The common characteristics of myofascial trigger points are the appearance of local and referred pain, reduction of muscle stretch and strength, autonomous symptomatology, and the differentiation of active and latent myofascial trigger points. Many interventions are proposed for treatment. A novel application being used, is Extracorporeal Shockwave therapy (ESWT). While there are two types of ESWT, radial type is nowadays frequently used. It is supposed that radial ESWT may positively affect the affected muscle, by increasing blood flow and reducing pain. Also, it is believed that ESWT may act on muscle cells permeability and Acetylcholine action in neuromuscular junction. While several studies exist regarding radial ESWT, no standard parameters are used or proposed in the literature.

Purpose: The purpose of this narrative review is to assess the parameters of radial ESWT on myofascial trigger points.

Methods: In the current review, randomized clinical or controlled trials were concluded for assessment. PubMed, CINAHL Plus and Sports Discus were searched, from inception to July 2020, for trials referred to the application of radial ESWT on myofascial trigger points. The inclusion criteria were that the trials referred to application on humans, written in English, referring only to myofascial trigger points and the radial ESWT. Exclusion criteria were for trials with fibromyalgia patients, animal interventions, studies not referring to radial ESWT and written in other than English language.

Results: Ten studies with a total sample of 534 subjects, met the inclusion criteria. Most of the studies propose that the device should be used once per week. Five studies have used the device for three sessions weekly. Other studies proposed different number of sessions with different time intervals. Most of the studies applied 1000 pulses per session, while there is a range of 400 to 4000 pulses. The energy density of most of the studies is low at 0,1 mj/mm2. The rest of the studies vary between 0.003 to 0.38mj/mm2. Two studies used 10 Hz as frequency, where 8-11 Hz are also used. All studies have used contact gel. Six studies referred to upper trapezius, one to various neck muscles, one to rotator cuff muscles, one to gastroc-soleus and one did not refer to any muscle.

Conclusion(s): The results of this review shown that there is a long range of each parameter setup. Although, there is little evidence about the format of the parameters. Moreover, the parameters are not extracted by all the included studies, but by combining them. More studies must be constructed in the future, for better conclusions.

Implications: According to the results of the current review radial ESWT can be used effectively for myofascial trigger points therapy. It is recommended that the device should be used by the parameters proposed in this review.

Funding, acknowledgements: None

Keywords: Myofascial trigger points, Extracorporeal Shockwave therapy, RSWT

Topic: Musculoskeletal

Did this work require ethics approval? No

Institution: European University Cyprus

Committee: European University Cyprus Ethics Committee

Reason: The study is a narrative review of the literature