How does ultrasound work the treatment head is then moved over the surface of the skin in the region of the injury transmitting the energy into the tissueswhen sound waves come into contact with air it causes a dissipation of the waves and so a special ultrasound gel is placed on the skin to ensure maximal contact between the treatment head and the surface of the skin andto provide a medium through with the sound waves can travel the most common conditions treated with ultrasound include