Physical Therapy Assistant Practice Exam 2025 – Complete Prep Guide

The primary concern regarding a high beam nonuniformity ratio during ultrasound therapy is that it can lead to hot spots or periosteal pain. A high beam nonuniformity ratio suggests that the energy distribution from the ultrasound transducer is uneven, which means that certain areas may receive significantly more energy than others. This uneven distribution can create localized regions of excessive heating, or "hot spots," which may not only cause discomfort but can also lead to tissue damage.

The periosteum, a membrane that covers the outer surface of bones, is particularly sensitive to changes in temperature. If the ultrasound energy causes these hot spots near the periosteum, it can result in pain and potentially harmful effects on the underlying bone and surrounding tissues. Therefore, ensuring a low beam nonuniformity ratio is critical for achieving safe and effective treatment outcomes in ultrasound therapy.