According to ultrasound principles, how does frequency affect penetration?

In the context of ultrasound principles, lower frequency is associated with greater penetration. This is because lower frequency sound waves have longer wavelengths, which can travel deeper into tissues without being significantly absorbed or scattered. In practical application, this means that when using ultrasound for therapeutic purposes, such as in esthetics or physical therapy, lower frequencies can reach deeper layers of the skin or underlying tissues.

Higher frequencies, on the other hand, provide a more superficial effect because they are absorbed by the tissues more quickly due to their shorter wavelengths. This characteristic makes higher frequency ultrasound more suitable for treatments targeting the upper layers of the skin rather than deeper structures. Thus, if the goal is to penetrate deeply into tissues for healing or therapeutic effects, lower frequency ultrasound is the preferred choice.