Title: Presentation of Acoustic Waves propagation and their effects through Human body tissues Author

Abstract Three types of acoustic waves are mainly used in the medical field, Extracorporeal Shock Waves (ESWs), Pressure Waves (PWs) and Ultrasound (US). Shock waves are acoustic waves that are characterised by high pressure amplitudes and an abrupt increase in pressure that propagates rapidly through a medium. The energy distribution on the treatment area differs from being wide over a large area, or concentrated on a narrow treatment zone, such influences the therapeutic and biological effect of the shock wave. Pressure waves are usually generated by the collision of solid bodies with an impact speed of a few metres per second, far bellow the speed travels the shock wave. There are major differences between PWs and ESWs, concerning not only their physical characteristics and the technique used for generating them, but also the order of the parameters normally used. The simulation effects and therapeutic mechanisms seem to be similar, despite the physical differences and the resulting different application areas (on the surface and in depth respectively). Ultrasound therapy is one of the modalities of physical medicine used for pain management and for increasing blood flow and mobility. Ultrasound and ESWs -PWs differ, despite their acoustic relationship, basically because ESWs -PWs appear large pressure amplitudes with direct mechanical effects and US propagates with periodic oscillations with a limited bandwidth, and mainly direct thermal effects. Acoustic waves, have direct mechanical and mechanotransduction effects on the cells and ECM increasing porosity, angiogenesis, releasing of growth factors, enhancing proteosynthesis and viscoelastisity and inducing histeogenesis and repair processes