**3. Mechanical vibration and vibration therapy**

Throughout the history of humanity, it can be verified that through various procedures, mechanical vibration has been added to a person's body such as manipulation techniques, and others related to breathing, such as coughing and percussion [11, 18].

The addition of mechanical vibration can be through devices that transmit the mechanical vibration locally. When the intervention aims to treat a complaint referring to a specific anatomical segment, it is called local or segmental vibration therapy [10]. When mechanical vibration is transmitted to the whole person's body, aiming for an improvement in the physical performance, or as a clinical intervention, there is the generation of whole-body vibration exercises [8, 12] and, the procedure is called Systemic vibration therapy. As it is shown in **Figure 4**, the biological effects of mechanical vibrations would be due to the mechanotransduction mechanism by which cells (cellular structures and inner environment of the cell) convert mechanical stimulus into biological activity and there is the release of various hormonal and no hormonal molecules [19].

This form of mechanotransduction would be responsible for a number of physiological processes in the body, including proprioception, effects on bone

**Figure 4.**

*Interaction of the mechanical vibration with the cell and the mechanobiotransduction.*

#### **Figure 5.**

*Some targets of the mechanical vibration in the body related to proprioception (2, 6, 7), effects on bone mineral density (6) and in the metabolism (3, 4), endocrine (2, 3, 4), and immunity systems (2, 7), muscle (6) and vital functions (1, 5), balance (2, 6, 7), and functionality (2, 6, 7).*

mineral density and in the metabolism, endocrine and immunity systems, muscle and vital functions, balance, and functionality. The mechanical vibration would be a physical agent that would lead to mechanobiomodulation of the physiological phenomena in various organs or systems as it is suggested in **Figure 5**. Mechanical vibration could act as an agent that promotes the modulation of biological effects through specific signaling pathways, as various hormonal and other substances. Vibration therapy might be considered a complementary intervention that can be used in the management of individuals with different health conditions.

## **3.1 Vibration therapy**

In vibration therapy, parameters mentioned previously must be considered. Additionally, the time of exposure to mechanical vibration in a session, the total time of the intervention, the number of exposures, rest time in each session, and the weekly frequency of the sessions must be considered. In the case of whole-body vibration exercise generated due to the Systemic vibration therapy, the person's position in relation to the platform must also be also considered [8].
