Ultrasound is most often associated with those cute baby pictures in a mother’s tummy, but therapeutic ultrasound in physiotherapy practice is an effective modality used to treat pain and other symptoms.
Therapeutic ultrasound in physiotherapy practice induces ultrasonic waves in the tissue to gain various biological effects. The waves produce mechanical energy through vibration or oscillation at fixed points.
How Does Ultrasound Work?
Ultrasound produces soundwaves that generate mechanical energy. These waves cause oscillation and vibration of the molecules after entering into the tissue. The oscillation results in heat generation that brings thermal and non-thermal changes.
Who Can Provide Ultrasound Treatment?
Physical therapist, occupational therapists, physical therapist assistants, and occupational therapist assistants are qualified to provide ultrasound treatment. Therapists should receive proper training on safe practice and determining the correct dosages for therapeutic effects. Specific trainings by the manufacturer may also be necessary to operate different ultrasound machines.
What are the Settings for Ultrasound?
Ultrasound can act as either a superficial or deep heating modality. Therefore, knowing the settings for appropriate use is important. A physiotherapist should know the mode, intensity, and duration to use the machine properly. Many ultrasound machines now have preset programs built for different symptoms and conditions. Depending on the settings you choose, ultrasound can generate thermal effects or non-thermal effects. For example, thermal effects can be achieved at a relatively higher intensity and in continuous mode. Contradictorily, non-thermal effects can be achieved at pulsed mode. In addition, lower intensity increases the depth of penetration compared to higher intensity. In other words, 1 MHz will penetrate down to 4 to 6 cm depth versus 3 MHz which penetrates to 2 cm into the tissue.
How to Perform Therapeutic Ultrasound in Physiotherapy?
Ultrasound is applied directly on the patient’s skin with a round-headed probe. Since ultrasonic waves require a medium for transmission, ultrasonic gel should be used on the probe. The probe has specialized crystals that are responsible for soundwave vibration and pass energy into the tissue, causing the therapeutic benefits. The following precautions should be followed when using ultrasound:
- The head of the applicators should be moving throughout the treatment.
- The ultrasound beam (treatment head) should be perpendicular to the treatment area for best results.
- All parameters (intensity, duration, and mode) need to be considered carefully for desired therapeutic effects. Consider using the lowest intensity to produce a therapeutic response.
When to Use Ultrasound?
Ultrasound is helpful in treating the following conditions:
- Inflammation (mainly bursitis or tendonitis)
- Chronic pain
- Ligaments injuries or sprains
- Muscle tears or strains
- Tightness or contractures (to improve range of motion)
- Frozen shoulder
- Wound healing
When Should Ultrasound Be Avoided?
Contraindications to ultrasound treatment include:
- Directly on open wounds or active infections
- Over metastatic lesions
- On patients with impaired sensation
- Directly on metal implants
- Near a pacemaker or any other device that generates a magnetic field
- During pregnancy (except in the instance of diagnostic sonography)
Additionally, ultrasound should not be applied over:
- The eye
- The gonads
- Active epiphysis in children
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