Which therapy modality provides deep heat within tissues by increasing molecular movement?

Which therapy modality provides deep heat within tissues by increasing molecular movement?

• A. Hot pack
• B. Fluidotherapy
• C. Paraffin
• D. US diathermy

Answer: (D)

Heating from this modality comes from energy absorbed by tissues that causes molecules to move more, producing heat in deeper layers. Ultrasound therapy sends high-frequency sound waves into the tissue; as these waves are absorbed, they cause microscopic vibration and friction among molecules, converting the mechanical energy into heat. Because of how ultrasound energy travels, it can target deeper tissues: lower frequencies (about 1 MHz) heat deeper structures, while higher frequencies (about 3 MHz) heat more superficially. In contrast, hot packs and paraffin rely on conduction from the skin inward, so they heat mainly the superficial layers. Fluidotherapy uses a circulating medium to transfer heat by convection, which also tends to affect more surface tissues. So the modality that provides deep heating by increasing molecular movement is ultrasound therapy.

Heating from this modality comes from energy absorbed by tissues that causes molecules to move more, producing heat in deeper layers. Ultrasound therapy sends high-frequency sound waves into the tissue; as these waves are absorbed, they cause microscopic vibration and friction among molecules, converting the mechanical energy into heat. Because of how ultrasound energy travels, it can target deeper tissues: lower frequencies (about 1 MHz) heat deeper structures, while higher frequencies (about 3 MHz) heat more superficially.

In contrast, hot packs and paraffin rely on conduction from the skin inward, so they heat mainly the superficial layers. Fluidotherapy uses a circulating medium to transfer heat by convection, which also tends to affect more surface tissues. So the modality that provides deep heating by increasing molecular movement is ultrasound therapy.