Ultrasound is a therapeutic modality that has been used since the 1940s. Ultrasound is applied using a round-headed wand or probe that is put in direct contact with the patient’s skin. Gel is used on all surfaces of the head to reduce friction and assist transmission of the ultrasonic waves. When using therapeutic ultrasound common frequency range is about 0.8-3.0 MHz.
The way ultrasound works is through vibration of crystals within the head of the probe. The sound waves that pass through the skin cause a vibration and are absorbed primarily by connective tissue such as: ligaments, tendons, and fascia. This vibration can cause a deep heating effect, but will not be felt by the patient. There are situations where a heating effect is not desirable, such as a fresh injury with acute inflammation, the ultrasound can be pulsed rather than continuously transmitted to prevent a heating effect.
In our office a typical ultrasound treatment will take 6-8 minutes depending on the size of the area being treated. In cases where scar tissue breakdown is the goal, this treatment time can be much longer. During the treatment the head of the ultrasound probe is kept in constant motion so that the patient feels no discomfort during treatment. If the probe is held in one place for more than just a few seconds, a build up of the sound energy can result which can become uncomfortable.
Conditions for which ultrasound may be used for treatment include:
- Ligament sprains
- Muscle strains
- Joint inflammation
- Plantar fasciitis
- Facet irritation
- Impingement syndrome
- Rheumatoid arthritis osteoarthritis
- Scar tissue adhesion
- Tissue relaxation
- Reduce swelling
Contraindications of ultrasound include local malignancy, metal implants below the area being treated, local acute infection, vascular abnormalities, and directly on the abdomen of pregnant women. It is also contraindicated to apply ultrasound directly over active epiphyseal regions (growth plates) in children, over the spinal cord in the area of a laminectomy, or over the eyes, skull, or testes.