Physical Agent Modalities Practice Exam

Non-thermal ultrasound reduces inflammation by delivering mechanical energy that triggers cellular activities involved in healing without raising tissue temperature. The low-intensity energy causes stable cavitation and acoustic streaming, which enhances cell membrane permeability and stimulates processes such as fibroblast activity, collagen synthesis, and angiogenesis. These actions help clear inflammatory mediators and edema, speeding the transition from the inflammatory phase toward tissue repair. As the inflammatory response subsides and fluid buildup resolves, the overall level of inflammation decreases.

Edema and pain can also improve as healing accelerates and fluids are mobilized, but the primary effect tied to this modality in the acute phase is the reduction of inflammatory activity. Scar tissue formation, on the other hand, relates more to remodeling and long-term collagen organization; non-thermal ultrasound can influence healing processes, but it isn’t the direct mechanism by which scar tissue is reduced in the short term.