Ultrasonic therapy works by converting electrical energy into mechanical vibrations using a piezoelectric crystal located in the ultrasound head. When applied to the skin, these vibrations generate high-frequency sound waves that penetrate deep into the tissues, resulting in both thermal and non-thermal physiological effects. The thermal effects include an increase in tissue temperature at depths of up to 5 cm, which promotes vasodilation, enhances blood flow, reduces muscle spasms and joint stiffness, and improves collagen elasticity, making tissues more flexible. The non-thermal (mechanical) effects involve cavitation—the formation of microscopic gas bubbles that stimulate cellular activity and increase membrane permeability—as well as acoustic streaming, which facilitates fluid movement around cells to enhance nutrient delivery and waste removal. Additionally, micromassage from the mechanical vibrations helps reduce inflammation and encourages tissue healing. Together, these effects support tissue regeneration, decrease inflammation, and enhance overall cellular function.