Dr. Martin's notes

Thursday January 26, 2017

Ultrasound Therapy

ultrasound - The application of sound waves to a body area to increase circulation and flexibility as well as to decrease pain and muscle spasms in that area.

Ultrasound is a high frequency sound wave that is converted to heat. Because it is one of the deepest penetrating heat sources available and can reach depths of 3 to 5 cm, ultrasound is one of the more commonly used modalities. Frequently used for sub-acute pain, inflammation, and muscle spasms, ultrasound therapy is applied with a sound head. A coupling medium is also used to help the sound waves penetrate the skin and stimulate the blood flow in the treated area.

There is a wide variety of coupling mediums available, including mineral oil solutions, water-soluble creams, and conductive gels. The coupling medium ensures an airtight contact between the skin and the ultrasonic waves generated by the mechanical head; it also reduces friction against the skin, which allows the sound head to glide smoothly over the body surface and provide an even distribution of heat. When using the water-soluble medium, the skin should be thoroughly washed and dried before applying the medium to prevent air bubbles that hamper the flow of the sound waves to the skin.

When using ultrasound, the sound head is moved in a slow circular pattern or a stroking method. It is very important to make sure that the sound head is kept in constant motion. If this head is left in one spot for a prolonged period of time, the patient could be burned or the ultrasound head can be damaged.

The intensity of the ultrasound varies according to the depth and density of the tissue and the type of the injury. Controls on the ultrasound machine allow the user to change settings to adjust to various depths and intensities. For example, 0.1 to 0.8 watts/cm2 is regarded as low intensity, while 0.8 to 1.5 watts/cm2 is medium intensity, and 1.5 to 3.0 watts/cm2 is high intensity. The duration of an ultrasound treatment is 3 to 8 minutes. These treatments can range from daily use to three times per week.

Ultrasound cannot be applied to high fluid areas of the body, such as the eyes, ears, genitals, brain, spinal cord, or heart. Reproductive organs in women who are pregnant must also be avoided. Acute injuries and areas with extremely poor circulation should not be treated with ultrasound. The epiphyseal plate areas in children, stress fractures, open wounds, hemhorrages, and infected, inflamed, or malignant areas also should not be treated with ultrasound.

Ultrasound therapy should not be applied to an area that exceeds 3" to 4" in diameter in one treatment. If the area treated is larger than 3" to 4", then the tissue does not receive the concentration of ultrasound needed for adequate treatment; in such cases, the ultrasound application will require more than one treatment.

Because airtight contact between the skin and the sound waves is so important, ultrasound therapy is applied underwater to irregularly-shaped body areas such as wrist, hand, elbow, ankle, and foot. The water provides an airtight coupling that allows the sound waves to travel at a constant velocity to the extremity, so no additional coupling medium is necessary. To accomplish this, the extremity is fully immersed in the water and the ultrasound head is positioned approximately 1" from the body part that will be treated. As with other ultrasound treatments, the sound head should be moved slowly in a circular or stroking pattern. Air bubbles that attach to the skin must be wiped away continually.