Which settings of an ultrasound are used for acute conditions?

• A. Thermal settings
• B. Non-thermal settings
• C. Pulsed settings
• D. Continuous settings

Answer: (B)

For acute injuries, the goal is to promote healing without adding heat. Non-thermal ultrasound delivers energy in a pulsed manner with a low duty cycle, which avoids tissue heating while still producing mechanical effects that stimulate the healing process. These mechanical effects—cavitation, microstreaming, and acoustic streaming—enhance cellular activity, increase membrane permeability, and support tissue repair and edema reduction. Heating the tissue with continuous (thermal) ultrasound can increase metabolic demand and inflammation, which is not desirable during the acute phase. Once healing progresses and stiffness or chronic pain become the focus, thermal settings may be used. So, non-thermal settings are the best fit for acute conditions.