Ultrasound therapy is a commonly used modality in physiotherapy that utilizes high-frequency sound waves, typically between 1 to 3 MHz, to treat various musculoskeletal conditions. It works through both thermal and non-thermal effects. The thermal effect generates deep tissue heating, which helps in increasing blood flow, reducing muscle spasms, and enhancing the extensibility of soft tissues such as tendons and ligaments. The non-thermal (pulsed) effect promotes cellular repair, reduces inflammation, and accelerates tissue healing, making it especially useful in the early stages of injury. Ultrasound therapy is indicated for conditions like tendonitis, bursitis, muscle strains, ligament injuries, joint contractures, and scar tissue management. It is applied using a sound head moved in circular or linear motions over the affected area with a coupling gel to facilitate sound wave transmission. Despite its benefits, ultrasound therapy should be avoided over certain areas such as the eyes, reproductive organs, open wounds, fractures (unless specified), and cancerous tissues. Overall, ultrasound is a non-invasive, effective technique that supports pain relief, tissue repair, and functional recovery in physiotherapy practice.