What is a recognized therapeutic effect of ultrasound?

• A. Increase range of motion
• B. Visualize internal structures
• C. Measure bone density
• D. Heat the eyes

Answer: (A)

Ultrasound therapy primarily provides a heating effect when used continuously. The energy raises tissue temperature, which increases the elasticity of collagen-rich structures such as tendons, ligaments, and the joint capsule, and decreases passive resistance in muscles. This makes soft tissues more pliable, so joints can move more freely and stretching can yield a greater range of motion. Therapists often use ultrasound before ROM or stretching activities to maximize gains.

Visualizing internal structures is diagnostic ultrasound, not a therapeutic effect. Measuring bone density isn’t achieved with therapeutic ultrasound, and heating the eyes is unsafe and not an intended use.