Ultrasound therapy is the use of sound waves to treat medical problems, especially musculoskeletal problems like inflammation from injuries (sprains, tendinitis, bursitis). It has been a popular therapy for decades, its use so widespread that it almost defines physical therapy. Unfortunately, although mainstream, it is not as scientific a treatment as most people assume. It has been condemned or, at best, damned with faint praise by one scientific review after another for a quarter century. Authors had almost nothing good to say about ultrasound. Conclusions like this one (from van der Windt et al) are the rule: “As yet, there seems to be little evidence to support the use of ultrasound therapy in the treatment of musculoskeletal disorders.” Some modern variants of ultrasound are expensive, hyped, and totally unproven for any or many conditions.