Ultrasound therapy uses sound waves in the high-frequency range of 1 to 3 MHz, which are used in physiotherapy because of their anti-inflammatory effect and to loosen adhesions.
The sound waves are above the human hearing frequency range, which is below 0.02 MHz.
The method for generating sound waves is the same as that used for ultrasound examination.
The device makes use of the inverse piezo effect.
When current flows through the quartz crystals contained in the device head, they undergo continuous mechanical deformation and, creating a vibration, emitting sound waves.
What is the principle of operation of ultrasound therapy?
When the sound waves enter the body, the vibration effect moves all internal particles and stimulates the reabsorption of the inflammatory fluid.
The sound waves give off energy as they penetrate the tissue and generate heat.
In addition, the permeability of the cell membrane is increased, which favors the entry of nutrients and the elimination of waste products.
The sound waves enter the body in inverse proportion to the frequency.
The sound waves with a frequency of 3 MHz act up to 1 cm below the surface, the sound waves of 1 MHz reach a depth of up to 3 cm. The application on the body is neither invasive nor painful.
What does the ultrasound device look like?
The ultrasonic device consists of a current generator and a transducer. The output power is between 0.1 and 3 watts. The duration of treatment is about 10-15 minutes. There are two different applications:
- with a movable sound or massage head, with which the physiotherapist runs over the patient’s skin and possibly exerts friction.
- with a fixed transducer, which is held by a mechanical arm and is used when the area to be treated is precisely circumscribed, such as a heel spur.
Typical indications are:
- Dupuytren’s disease,
- osteoarthritis,
- inflammation of the joints,
- tendonitis,
- inflammation of the joint capsule,
- bursitis,
- organized bruising and scar tissue,
- back pain,
- periarticular calcium deposits at the initial stage.
There are studies on the use of ultrasound therapy for shin fractures, which testify to a reduction in bone healing times of up to 35-40%, but the duration of treatment is 2-3 hours daily.
Contraindications include:
- Osteoporosis with high substance loss
- Presence of metal parts
- Joint prostheses
- Varicose veins
- Vein inflammation (phlebitis and thrombophlebitis)
- Tumoral and adjacent tissues
- Pregnancy
