Final answer:
Ultralu is not specifically mentioned in the information provided, but high-intensity ultrasound is commonly used for deep-heat treatments in athletics and physical therapy to relieve pain and improve flexibility.
Step-by-step explanation:
Ultralu is not specifically mentioned in the given information, but high-intensity ultrasound, similar to Ultralu, is commonly used for deep-heat treatments called ultrasound diathermy in both athletics and physical therapy. It is applied to injured or overworked muscles to relieve pain and improve flexibility. Care must be taken to avoid tissue damage caused by overheating, cavitation, and reflection of the ultrasound by joint and bone tissue.