Vibration Therapy for Health Promotion

Abstract

Vibration therapy has been used as a clinical intervention, in which mechanical vibration is transmitted to a part or to the whole body of the individual. It is very important to point out that mechanical vibration is a natural stimulus that is part of the daily life of all living beings and is periodically added to the organism due to a movement of the body. When, for several reasons, the person cannot add mechanical vibration to the body, the mechanical vibration generated by a device can be transmitted to the person in contact with it. When the intervention aims to treat a complaint referring to a specific anatomical segment, it is called local or segmental vibration therapy. However, when mechanical vibration is transmitted to the whole person’s body, aiming for an improvement in the performance, or as a clinical intervention, the procedure is called Systemic vibration therapy. The biological effects would be due to the mechano-transduction mechanism by which cells convert mechanical stimulus into biological activity, releasing various hormones and other substances. This form of mechano-transduction is important to physiological processes in the body, including proprioception, effects on bone mineral density, muscle, balance, and functionality, promoting the modulation of biological effects through specific signaling pathways. In this chapter, the use of mechanical vibration as an intervention aiming to improve and optimize daily life is discussed, either as a local or systemic application, targeting a specific part of the body or the whole body, respectively.

1. Introduction

Technological development in different areas of knowledge has led to the emergence of new procedures that have been progressively incorporated into professional activities in different sectors, including in health sciences. As a consequence, everyone must be prepared to be challenged and use what technological advances have to offer, providing better living conditions for all people who need help to improve their health condition and quality of life. Knowledge about potential benefits and limitations will guide the best way to take advantage of new technologies [1, 2, 3]. Thus, the establishment of safety-related criteria that must be followed together with the update in the level of evidence of related publications will guide the effectiveness of the procedure with the safe use of the technique without adverse events [4, 5, 6, 7].

Particularly, in the health sector, these challenges have a special dimension. Health professionals must be able to critically analyze the available information to choose the safest and most beneficial interventions, incorporating scientific evidence, clinical expertise, patient preferences and values to make decisions. This is the basis for evidence-informed practice, which allows patients to have the maximum benefits from these new technologies without being subjected to unnecessary risks [5, 6, 7]. Vibration therapy, is an example of a technological intervention, supported by research findings and with neglectable risks for the patients [8, 9, 10].

The exposition of the body to mechanical vibration, as a clinical intervention, is not recent, but the use of mechanical vibration in the context of health promotion (in different conditions), with well-defined criteria started in 6th decade of the last century. Vibration therapy has been used as a clinical intervention, in which mechanical vibration is transmitted to the part [10] or whole body [11, 12] of the individual. Specific biomechanical parameters, position of the individual, exposition and rest time, and periodicity are established according to the condition to be treated and the desired effect. Whole-body vibration exercise is an exercise promoted on a vibrating platform, while mechanical vibration is being transmitted [8, 9, 12].

2. Mechanical vibration

2.1 General characteristics

Mechanical vibration is a physical agent of wave nature. It can be produced by different devices, such as a refrigerator engine, a motor vehicle engine, an air conditioner, and others. A vibrating platform is one of such examples. In all the examples provided, the device is outside the person’s body, but if the person is in contact with it, the mechanical vibration is transmitted to the person [11, 12]. As shown in Figure 1, the waveforms of mechanical vibrations produced by different devices, can be deterministic (Figure 1A) or random in nature.

Figure 1.

Different waveforms related to mechanical vibration.

The mechanical vibration, that is generated in a vibrating platform [11, 12] or portable [10] devices, is characterized by the sinusoidal form, and this deterministic approach has particular interest for everything that will be covered in this book chapter on vibration therapy.

2.2 Mechanical vibration as a daily stimulus

It is very important to highlight that mechanical vibration is a natural stimulus that is part of the daily life of all living beings and is periodically added to the organism during movements [11, 12]. It is closely associated with the physiological responses of all organisms, including human being. The addition of mechanical vibration happens in a wide number of routine situations [11], such as walking, running, playing, being in a car or public transport, or doing a domestic activity, such as using a vacuum cleaner for cleaning or a fruit extractor while making a juice. Likewise, in professional activities such as driving a car, truck, train, or using dental equipment, mechanical vibration is transmitted to the individual that is in contact with the device that is producing the referred vibration [13, 14]. In addition, several structures of the human body naturally produce mechanical vibrations, such as the heart, digestive system, the shortening and stretching of muscle fibers, vessels of the vascular system, the vibrational energy of electrons in a chemical bond, or the vibration of molecules in the cellular metabolism. Likewise, many of the organic functions depend on mechanical vibrations at different levels of anatomical structures [12, 15, 16]. Of course, in general, this addition of mechanical vibration is not fully perceived by the person, but when a movement is performed, mechanical vibration is added to the body. However, in some activities like walking or running, when the foot contacts the floor, mechanical vibration is more easily perceived. It may be relevant to consider that this addition of mechanical vibration would be the trigger for organic functions to take place and for the person to live with physical and mental health [12, 16].

When, for several reasons, the person cannot add mechanical vibration to the body, the mechanical vibration generated by a device can be transmitted to the person in contact with it. This procedure corresponds to a clinical intervention called vibration therapy [10, 11, 12].

2.3 Biomechanical characteristics of mechanical vibration

Vibration therapy, which is considered in this chapter, uses mechanical vibration, which is a physical agent that transports energy and is characterized by a displacement in relation to an equilibrium position with an oscillatory, sinusoidal, and deterministic movement, as shown in Figure 2.

Figure 2.

Sinusoidal waveforms related to mechanical vibration.

In this case, biomechanical parameters such as frequency, amplitude, and peak-to-peak displacement can be conveniently adjusted depending on the outcome to be achieved and the individual’s clinical conditions. These parameters need to be considered when designing a vibration therapy intervention protocol [8].

Frequency (f) is expressed in Hertz (Hz) and represents the number of cycles in one unit of time, for example, the second. Peak-to-peak displacement (D) is the measure of the perpendicular extension between the largest and smallest displacement of mechanical vibration expressed in millimeters (mm). The amplitude represents half the peak-to-peak displacement and is also expressed in mm. These parameters are represented in Figure 3. The path of the mechanical stimulus between the successive points Z1 and Z2, defines the cycle developed by the vibration. The number of cycles performed in the unit of time is the frequency [8, 11, 12]. An important observation is that at Z2, the stimulus begins again to have the same characteristics as point Z1.

Figure 3.

Representation of a sinusoidal mechanical vibration.

The distance comprised by the straight-line segment between points Z1 and Z2, measured, for example, in mm, is defined as the wavelength of the mechanical stimulus. This corresponds to the projection of the entire cycle on the propagation plane. It is important to consider that in the International System of Measurements, the wavelength value would be expressed in meters. Considering the perpendicular measure between the highest point or the lowest point (x1) of the mechanical vibration and the propagation plane or the lowest point (x2) is the amplitude. The perpendicular of the point X1 up to the level of the x2 is the displacement peak-to-peak. The value of the displacement peak-to-peak corresponds to twice the amplitude [17].

The peak acceleration (Ap) of mechanical vibration depends on the frequency and the peak-to-peak displacement and is normally expressed in multiples of gravity (xg). The peak acceleration can be determined using accelerometers, or according to the equation Ap = 2 x π2 x f2 x D [17]. Peak acceleration allows defining the intensity or magnitude of mechanical vibration and of the vibration therapy.

Two mechanical vibrations, with the same frequency, with displacement with correspondences in points X1 and x2, are said to be in phase. On the other hand, when these coincidences do not occur, the two stimuli are out of phase. These considerations are relevant, in the same way, the stimulus generated in the platform has its own amplitude, the medium being crossed also presents mechanical vibration.

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].

Figure 4.

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

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

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).

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].

3.1.1 Devices used in vibration therapy

3.1.1.1 Local vibration therapy

The devices used in local vibration therapy are relatively simple and are small, and in general, are portable devices device that applies vibration directly over the muscle or the tendon [20]. Buttons are available for selecting the operational conditions of the intervention characteristics, which consider the frequency of mechanical vibration. Local vibration therapy is very important for several individuals that are in long-term immobilization, immobilization by a cast, or being in the early rehabilitation period after surgery [10, 20].

3.1.1.2 Systemic vibration therapy

The device used in Systemic vibration therapy is a vibrating platform. Systemic vibration therapy is a clinical intervention in which mechanical vibration generated on a vibrating platform is transmitted to the entire body of the person who is in contact with the base of the platform producing the whole-body vibration exercise in the individual [8, 12, 16].

There are two main types of vibrating platforms, which are shown in Figure 6A and B. Figure 6A represents a vibrating platform where the base performs a movement with vertical displacement as a result of the force applied. The oscillating of this base can be vertical or triplane way. Figure 6B has demonstrated the side alternating vibrating platform, where the base performs side alternating movements (up and down) [8, 12, 16].

Figure 6.

Vibrating platforms and oscillation of their bases.

In the side alternating vibrating platform, the base rests on a central fulcrum. When turned on, while the right side of the base goes up, the left side goes down, generating mechanical vibration, like a seesaw. The mechanical vibration is then transmitted to the individual who is in contact with the base, and this platform is called the side alternating platform [8, 12, 16].

In the vertical platform, the whole base of the platform goes up and down which is called the vertical displacement type. This vertical displacement may be due to a simple displacement of the base, lowering and raising. In this case, the vibrating platform is called a synchronous vertical type of platform. This vertical displacement can also be a result of the base displacement in three planes. In this case, the platform is named the triplane vertical platform [8, 12].

It is easy to verify that, associated with the mechanical vibration, a force is generated, which is responsible for the displacement of the base of the vibrating platform, and it is transmitted to the person’s body. This force arises from the action of the acceleration imposed by the vibrating platform on the body, which has a certain mass [8, 12, 16].

3.2 Local vibration therapy

Local vibration therapy could be an alternative form of vibration training for individuals that are unable to perform systemic vibration therapy. The main interest of Local vibration therapy compared to Systemic vibration therapy is that it does not necessarily require any active contribution from the participant. Local vibration therapy is not an entirely novel concept and in fact, it has been used for a long time in the field of neuroscience. Indeed, Local vibration therapy applied to the tendon can induce several physiological effects such as a tonic vibration reflex or muscle movement illusion depending on the experimental setup [10, 20, 21].

3.3 Systemic vibration therapy

In Systemic vibration therapy, the mechanical vibration produced on the vibrating platform is transmitted to the person generating an exercise throughout the whole body of the individual, the whole-body vibration exercise. Typically, the person has their feet positioned on the base of the vibrating platform, being in an orthostatic position with knees bent or sitting in an ancillary chair positioned in front of the platform [8].

There is a scientific evidence that Systemic vibration therapy can (i) improve muscle strength and potency, sleep quality, peripheral blood circulation, flexibility, functionality, balance, postural control, and quality of life; (ii) reduce pain, muscle fatigue, the risk of falling, and (iii) increase muscle fiber recruitment and bone mineral density [8, 12, 16, 22].

4. Conclusion

In this chapter, we discussed the use of mechanical vibration as an intervention aimed to improve and optimize daily life. This vibration therapy can be used as a local application of mechanical vibration, to the whole body and as Systemic vibration therapy. Vibrational movements are present in our everyday life. Using these concepts of vibrational analysis, their understanding and optimization represent a challenge in bringing individuals to an original way of natural therapy.