An abnormal increase in fluid (interstitial) volume is Edema (Tortora, Gerard). It can be caused when increased capillary blood pressure causes more fluid to be filtered, increased permeability of capillaries, or with inadequate re-absorption causes the decreased concentration of plasma proteins and lowers the blood colloid osmotic pressure (Tortora, Gerard). Edema is normally only detected when an increase of 30 percent increase of fluid (Tortora, Gerard). Physical therapy uses ultrasound to help redistribute the excess fluid.
The ultrasound is a high frequency sound waves that are more than 20,000 Hz. (Greatlakes). When using ultrasound in physical therapy the frequency ranges between 0.9-3 MHz (Greatlakes). Ultrasound helps by breaking up scare tissues, reduces inflammation and swelling, helps with healing at the cellular level by increasing flow, and helps improve blood flow (Greatlakes). The therapist normally uses ultra sound before the start of physical therapy treatment because it also helps with relaxation of that treatment area.
The ultrasound uses a high-frequency generator that provides electrical current to a transducer that contains a piezoelectric crystal (Greatlakes). The crystal provides the compression wave when it vibrates because of the crystal being exposed to electricity (Greatlakes). The therapist can control how deep the wave goes by turning up or down the frequency (Greatlakes). The therapist can target the specific are needed to help reduce the problem area by encourging the extra fluid to flow out and disperse.
Greatlakes-Physiotherapy.com/physiotherapy –ultrasound.com./physiotherapy.html. UltraSound in Physiotherapy.7-2013.
Tortora, Gerard J., Derrickson, Bryan. Principles of anatomy and Physiology 13th ed. John Wiley and Sons, INC. 2011. 814.