Pulsed ultrasound at 3 MHz would be MOST indicated for which condition?

• A. A 42-year-old female with decreased ankle ROM due to tight gastrocnemius/soleus
• B. A 24-year-old female with patellar tendonitis
• C. A 32-year-old male with decreased knee ROM after cast removal
• D. A 22-year-old male with a chronic hamstring strain

Answer: (B)

Pulsed ultrasound at 3 MHz is best suited for superficial structures where you want non-thermal or mild thermal effects to enhance healing without overheating the tissue. The patellar tendon sits just beneath the skin near the knee, so a 3 MHz beam can efficiently target it. In tendinopathies like patellar tendonitis, pulsed delivery provides mechanical effects that promote cellular activity and collagen remodeling without a large temperature rise, supporting tissue repair.

The other scenarios involve deeper or different tissue needs. Deep hamstring tissue would require lower frequency (1 MHz) to reach it effectively, so 3 MHz wouldn’t adequately treat a chronic hamstring strain. Knee ROM limitations after cast removal are often due to joint and widespread soft tissue stiffness rather than a superficial tendon issue, and while ultrasound can help, it’s not as direct or impactful in this setting. Tight calf muscles are more about muscle length and extensibility, for which stretching and, if used, heating via continuous ultrasound would be more typical than pulsed 3 MHz.

So, the most appropriate use of pulsed ultrasound at this frequency is for patellar tendonitis.