Vibrotherapy in the treatment of musculoskeletal disorders: an overview of in vitro and in vivo studies

Due to at least economic factors, there is a growing need for effective and simple therapies for the increasingly common musculoskeletal (MSK) disorders, such as in the case of osteoporosis. Vibrotherapy seems extremely promising, at least for some patients, where therapeutic vibration (TV)* is increasingly used to improve bone structure and muscle performance. However, this form of physical therapy is poorly understood in terms of its mechanisms of action. Thus, scientists from the University of Leeds (England) reviewed an extensive and reliable literature of some of the effects of TV in vivo (in the context of the MSK system) and in vitro (osteogenesis, adipogenesis or interactions related to bone marrow mesenchymal stem cells, MSC).

• Many studies show the beneficial effects of TV on the MSK system with the acceleration values ​​of 0.3 g and the frequency of 45 Hz. Higher vibration frequencies, like 90 Hz, also seem to be favorable, but at lower acceleration values ​​(around 0.2 g).
• On the other hand, accelerations higher than gravity (> 1.0 g) may be responsible for the negative vibration effect on bones.
• There is a growing body of evidence that TV can influence the differentiation of stem cells, especially MSCs.

* {In the original text of the presented article, TV is described as low magnitude, high frequency vibration (LMHFV). However, the terms “low” and “high” are too relative in the discussed context. We are talking here about frequencies up to several dozen Hz and amplitudes in mm, and there are therapies that use vibrations of many times greater frequencies and many times smaller amplitudes. Therefore, the editors decided to use, perhaps a more appropriate term – TV, instead of LMHFV. Editorial note.}

Prepared on the basis of:

Vibration stimuli and the differentiation of musculoskeletal progenitor cells: Review of results in vitro and in vivo. Edwards JH, Reilly GC. World J Stem Cells. 2015;7(3):568-582.

More and more publications show that physical therapy with the use of TV {ie vibrotherapy; editorial note} improves a number of functions in the MSK system. This type of physical therapy is relatively simple to apply, cheap, often surprisingly quickly brings measurable results and is suitable for people with weak bones or mobility.

Various TV parameters are used in in vivo studies. Many studies show the beneficial effects of TV on the MSK system at 0.3 g acceleration and 45 Hz frequency. Higher TV frequencies, like 90 Hz, also seem effective, but with lower acceleration values ​​(about 0.2 g). Moreover, it is suggested that accelerations higher than gravity (> 1.0 g) may have negative effects on bones and may be perceived as somewhat unpleasant by patients.

In in vitro studies, as in the case of in vivo studies, the applied TV parameters and experimental conditions are very diverse, which makes it difficult to precisely define conclusions. However, there is a growing body of evidence that TV can influence the differentiation of stem cells, especially MSCs.

Comment

In conclusion, the authors of the presented review note that the use of TV to improve the function of the MSK system is promising, especially in weaker patients with difficult access to physical activity or exercise therapy. However, in this discipline of medical sciences, appropriate research should still be carried out, both on humans and in paired animal models in vivo and in vitro, in order to understand the mechanisms, isolate appropriate schemes and ranges of TV parameters, and, apart from understanding the benefits for patients, also define possible unwanted side effects.

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