Therapeutic Laser and Ultrasound

We’ll be discussing the energy therapies of the modality world today: therapeutic laser and ultrasound

  • Therapeutic laser – this works similarly to a hot pack. Honestly does not provide much benefit
  • Ultrasound – less efficient than a laser and/or a hot pack. Waste of time

Therapeutic Laser

Observe this handsome man getting his ankle heated up

Therapeutic laser uses electromagnetic radiation which the mitochondria of the cells absorb. This is then dissipated as heat so the therapeutic benefits will be similar. In short, laser shoots light at the cells –> cells absorb light –> cells then convert light to heat. The primary goal of laser is to improve circulation and then therefore speed up the healing process.

  • 400nm is violet
  • 450 nm is blue
  • 650-700nm is red

I’ll quickly touch on the light spectrum for those that care. Light is measured in nanometers (nm). Visible light ranges from 400-700nm. Different wavelengths produce different colors. Therapeutic laser uses near infrared light so they will be in the 800-2,500nm range. The most commonly used wavelengths are 810, 980, and 1064 nm respectively. The greater the wavelength the deeper the penetration.

  • 810nm – help blood cells carry oxygen, rapid activation of hemoglobin
  • 980nm – increases calcium within cell wall, helps ease pain, stimulate circulation and
  • enhance muscle relaxation
  • 1064nm – all of the above just at a deeper level in the tissue

In short, laser works similar to heat, just at a more precise and deep level in the tissue. Also, lasers are cool. The best data for laser shows its excellent for wound healing and chronic pain


Ultrasound is a heating modality that uses acoustic (vibrations) energy to cause friction in
the cells that then leads to a temperature increase. Similar to light wavelength, ultrasound uses different frequencies to reach different tissue depths

High frequency (3MHz) has a higher absorption rate so it works more superficially. This works at a tissue depth of <3cm and the treatment takes 3-4 minutes

Low frequency (1MHz) has a lower absorption rate so it works at deeper levels in the tissue
This works at a tissue depth if 5-7cm and the treatment takes 10-12 minutes

The downside of ultrasound is how small of an area you can treat. The size of the tissue you can treat in a single treatment is 2-3x the size of the ultrasound head. This will net you a small area in the ballpark of 2×2″

Notice how small the head of the ultrasound is. Hard to treat a big area with that

At the end of the day, this is something I never use in practice. It is very inefficient as a heating modality and the area that can be treated is incredibly small