Non-thermal effects facilitate healing by what mechanism?

• A. Biophysical changes
• B. Heating
• C. Inflammation
• D. Necrosis

Answer: (A)

Non-thermal effects promote healing through biophysical changes in cells and tissues without raising tissue temperature. Modalities like pulsed ultrasound, electrical stimulation, or light-based therapies deliver energy in a way that mechanically or electromagnetically interacts with cell membranes, the extracellular matrix, and signaling pathways. This leads to altered membrane permeability, ion transport, and activation of cellular signaling that governs inflammation, collagen synthesis, and angiogenesis. The result is enhanced cell activity and tissue repair without heating the tissue. Heating would be a thermal mechanism, while inflammation is part of the healing process and necrosis is tissue death, neither of which explain how non-thermal energy drives repair.