Which modality is commonly used to reduce joint stiffness and improve tissue elasticity in chronic conditions?

• A. Cryotherapy to reduce inflammation only.
• B. Electrical stimulation to cause muscle contraction.
• C. Ultrasound non-thermal effects only.
• D. Thermotherapy (heat) to increase tissue extensibility, often paired with stretching.

Answer: (D)

Thermotherapy works by warming the tissues, which makes collagen and other connective tissues more pliable. When tissue temperature rises, viscosity decreases and the collagen fibers become more extensible, so a stretch performed after heating allows greater lengthening with less resistance. This combination—heat to prepare the tissues and stretching to exploit the increased elasticity—helps reduce joint stiffness and improve overall tissue mobility in chronic conditions where the tissues have become less compliant over time. Heat also boosts blood flow and metabolic activity, supporting readiness for movement and reducing the feeling of stiffness. In contrast, cryotherapy targets inflammation and pain but tends to stiffen tissue, electrical stimulation is mainly about activating muscles rather than changing passive tissue elasticity, and non-thermal ultrasound effects don’t reliably enhance extensibility without a heating component.