What is the main purpose of therapeutic ultrasound?

• A. To decrease blood flow
• B. To stimulate neural conduction
• C. To create cavitation in tissues
• D. To raise the temperature of structures such as tendons, ligaments, and joint capsules

Answer: (D)

Therapeutic ultrasound is used primarily to heat tissues. The main aim is to raise the temperature of structures with a lot of collagen—like tendons, ligaments, and joint capsules—so their collagen becomes more extensible. This helps with stretching, reduces stiffness, and supports healing by increasing blood flow and metabolic activity in the area. While there are non-thermal effects and, at times, energy can cause microcavitation, those are not the primary goal and are typically minimized in therapy. The other options describe effects that aren’t the main purpose: decreasing blood flow isn’t the goal, stimulating neural conduction isn’t the primary objective, and cavitation is something to avoid as the intended outcome.