In general we can distinguish direct effects and indirect effects of shock waves:
Direct effects: The first effect of shock waves is of a direct mechanical type: the positive pressure peak acts above all at the interface between tissues with different impedances (bone and soft tissues for example) paediatric physiotherapy singapore.
Indirect effects: The second effect, much more important from a clinical point of view, is indirect and is mainly due to cavitational phenomena that trigger the production of free radicals and nitric oxide (NO) with vasodilating and neoangiogenetic action.
The mechanism of action is also profoundly different depending on whether the target is a non-viable structure (eg a kidney stone) or a living tissue (eg a tendon).
In the first case, as occurs for example in lithotripsy, kidney stones, inert and very hard calcified concretions, when hit by waves regulated at suitable energies, disintegrate until they are expelled as smaller fragments.
This appears to be due more to direct effects.
Living tissues, on the other hand, such as bone, muscles, tendons and ligaments, when reached by the waves (at energy levels appropriate to the treatment site), do not suffer damage or shatter as happens for kidney stones. In this case, indirect effects are prevalent.
WHY DOES IT WORK IN PHYSIOTHERAPY?
The vital tissues treated undergo a series of micro-traumas that act as a sort of “micro-whirlpool” that triggers a series of cellular reactions, enzymatic cascades and biochemical reactions with the production of mediators and growth factors that lead to an anti- inflammatory, anti-pain and anti-edema.