**As with any modality or specialty intervention, you should always seek training and continuing education before using the approach on a patient**

Physical Agent Modality: Ultrasound

Ultrasound (US) is a common physical agent modality used in Occupational Therapy. It involves an ultrasound unit and transducers. The ultrasound unit and transducer creates sound waves that penetrate tissues of the body, and causes vibrations of the molecules within the tissues receiving the sound waves. Therapist can manipulate frequency, duty cycle, dosage, treatment duration, and treatment area to achieve different outcomes, such as non-thermal and thermal ultrasound. The transducer must maintain contact with the skin throughout the entire treatment session. The treatment area is three times the size of the transducer head, and a high viscosity gel, lotion, oil, or liquid must be used for the ultrasound to transmit into the intended bodily tissue.

Effects of Non-thermal US:

  • Stimulation of tissue regeneration
  • Increased macrophage responsiveness
  • Pain relief
  • Soft tissue repair
  • Increased blood flow
  • Increased skin/ cell membrane permeability

Effects of Thermal US:

  • Increased extensibility of collagen structures
  • Decreased joint stiffness
  • Pain relief
  • Increases blood flow
  • Decreased muscle spasms

Indications for US:

  • Soft tissue repair
  • Contracture
  • Bone fracture
  • Dermal ulcer
  • Scar tissue
  • Pain
  • Plantar wart
  • Muscle spasms

Contraindications for US:

  • Over eyes
  • Over pregnant uterus
  • Over prosthetic joint
  • Impaired circulation
  • Thrombophlebitis
  • Impaired pain/ temperature sensory deficits
  • Over heart
  • Over testes
  • Over epiphyseal areas in children
  • Infection
  • Malignancy

Cleaning Transducers on US Unit:

  • After every exam, completely wipe off all acoustic coupling gel before disinfecting.
  • Remove transducer cover, biopsy guides, or protective devices.
  • Use a moistened cloth or wipe to remove any remaining contaminants that are still on the transducer. Soap, detergents, or enzymatic cleaners should be used in accordance with the manufacturer’s instructions.
  • If rinsing is required, use caution not to expose the system connector to moisture or liquids.
  • Use a lint-free soft and clean dry cloth or wipe to thoroughly dry the transducer.
  • Any cleanser used on the transducer should be as close to a neutral pH as possible.
  • Do no use a brush or any device with bristles, since it may damage the transducer.
  • Research possible reactions with cleansers and products commonly used on patients’ skin.
  • The following materials found in many cleaning products may cause damage to the transducer: methanol, ethanol, benzyl or methyl alcohol, bleach, methyl or ethyl paraben, polyethylene glycol, mineral oil, lubricant oil, oil based lotions, acetone, ammonia, anhydrous ammonia, iodine, iodine compounds, acids with 5 pH or greater.
  • The attached document is a list of disinfectants that have been approved by the FDA. The optimal ultrasound cleanser would be one from the FDA list that doesn’t have any of the materials that were previously listed.


GE Healthcare. (2012). Ultrasound Transducers: Care, Safety, and Cleaning. Retrieved on July 23, 2012 from http://www3.gehealthcare.com/en/Products/Categories/Ultrasound/Ultrasound_Probes.

U.S. Food and Drug Administration. (2009). FDA-Cleared Sterilants and High Level Disinfectancts with General Claims for Processing Reusable Medical and Dental Devices. Retrieved on July 23, 2012 from http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/ReprocessingofSingle-UseDevices/ucm133514.htm

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