FROM MY PT SCHOOL NOTES · MODALITIES · UNIT 2 · CHAPTER 07
What Does Therapeutic Ultrasound Actually Do?
Learn acoustic-wave physics without assuming that the machine guarantees recovery.
At a glance
FREQUENCY
Acoustic wavelength and attenuation
PULSE / DUTY
On-time and average output
OUTCOME
Function, not machine warmth
What matters most
- Therapeutic ultrasound delivers acoustic, not electromagnetic, energy; frequency, intensity, pulsing, treatment area and coupling change exposure.
- Higher frequencies generally attenuate sooner and are used for more superficial targets; pulsing changes average delivery, not guaranteed clinical effect.
- Heating a tissue or changing local physiology does not by itself prove meaningful pain relief or function.
Safety and evidence limits
The 2020 Cochrane review and WHO guidance do not support routine ultrasound for chronic nonspecific/primary low-back pain; this does not establish efficacy or inefficacy for every other diagnosis. Avoid historical ‘recipe’ settings.
Updated evidence context: Cochrane review (2020) and WHO chronic primary low-back pain guideline recommend against treating ultrasound as routine care for that specific population. These conclusions should not be generalized to every condition.
Try a clinical decision
Scenario: A patient with persistent nonspecific low-back pain wants ultrasound to fix the problem. How would you respond?
Reveal the reasoning
Discuss the limited evidence for this indication, prioritize exercise and self-management, and specify a functional outcome rather than promising structural healing.
My original class sources: 9 Ultrasound.pdf; external context: Cochrane 2020 and WHO chronic primary low-back guideline. Supplementary context is not part of the original lecture packet. Educational summary, not a clinical protocol or device-setting guide.
