Physio And Ultrasound Therapy

Ultrasound Therapy As Used By Physiotherapists?

Ultrasound therapy in physiotherapy is the utilization of sound waves to help stimulate a healing response. As a result, this from of ultrasound is referred to as therapeutic ultrasound. The sound waves utilized in therapeutic ultrasound, sit above the range capable of being detected by human hearing. Sound waves like this have been used for decades by physiotherapists to help treat musculoskeletal problems.

Normal human audible range is considered to range from 16Hz to around 15-20,000Hz. Beyond this upper limit of 20,000Hz mechanical vibration generated via a therapeutic ultrasound machine is referred to as ultrasound. Frequencies used in physiotherapy, are are typically 1.0 MHz and 3.0 MHz. Indicating the sound waves are operating at 1-3 million cycles per second.

Stimulating Tissue With Ultrasonic Waves

The basic principle of ultrasound therapy as a healing aid, is about “stimulating” tissue using high frequency sound waves. The ultrasonic waves are produced by means of mechanical vibration in the metal application head. During treatment, your physiotherapist moves the application head in slow rhythmical circular motions. Targeted over the treatment area, so thereby transmitting the energy into the tissues below. Ultrasound coupling agents are used between the application head and the skin. This is because when ultrasound waves meet air, it causes a dissipation of these waves. The most common coupling agent is an aqueous gel. The coupling gel helps ensure maximal contact between the treatment head and the surface of the skin. Providing a medium through which the sound waves can travel, passing into the body.

Note: Ultrasound can also be applied under water. Seeing as water is another medium ultrasound waves can travel through. Therapeutic ultrasound may be used in this way when dealing with difficult to treat areas. This can include the hand and toes. Areas that are difficult to treat, maintaining consistent contact when using a coupling gel.

What Injuries Is Ultrasound Therapy Used To Treat?

Therapeutic ultrasound is used in physiotherapy to treat a variety of musculoskeletal conditions. Research has shown the modality to cause an increase in tissue healing rates, and scar tissue breakdown. Some common applications are to apply ultrasound to:

• ligament sprains
• muscle strains
• and soft tissue bruising, like heamatomas

Seeing as ultrasound can cause an increase in tissue activity, certain situations contraindicate the application of ultrasound therapy. Including:

• Treatment over an area of acute infection
• Application over local malignancy
• Treatment where there are any underlying metal implants
• Use on individuals with vascular abnormalities
• Application directly on the abdomen of pregnant women
• It is also contraindicated to apply ultrasound directly over active growth plates. So caution is needed in using ultrasound therapy on children.
• It is also contraindicated over the eyes, skull, or testes.

When used by highly trained professionals, therapeutic ultrasound is very unlikely to cause any adverse effects.

How Does Ultrasound Therapy Work?

The therapeutic effects of ultrasound therapy are generally divided into two categories. Effects that are thermal, and non thermal.

Thermal Effects Of Ultrasound Therapy

Sound waves are longitudinal waves consisting of areas of compression and rarefaction. Tissues exposed to a sound wave will oscillate. Doing so as the energy within the sound wave is passed into the tissue. An increase in the molecular vibration in tissue due to ultrasound therapy can result in the production of heat in the tissue. Thus ultrasound can be used to produce thermal changes in tissues.

As an ultrasound wave passes through tissues, energy levels within the wave diminish. Diminishing as energy is transferred to the tissues. So, tissues sitting deeper from the skins surface are exposed to less ultrasonic energy than superficial tissues. This fact necessitates appropriate selection of treatment frequency, relative to the target tissue. And is vital for the effectiveness of the therapy, because the different frequencies 1.0 MHz, and 3.0 MHz have different depths of penetration.

Which human tissues are the most effectively heated via ultrasound?

• Periosteum
• Collagenous tissues (ligament, tendon & fascia)
• Fibrotic muscle tissue

Non-Thermal Effects Of Ultrasound

As well as ultrasound therapy having above-mentioned thermal effects. Ultrasound as an electrotherapeutic device is reported to have non-thermal effects too. Ultrasound treatment is thought to accelerate the inflammatory process. By attracting more mast cells to the site of injury. And may cause an increase in blood flow, which can be beneficial in the sub-acute phase of tissue healing.

Ultrasound may also stimulate the production of collagen. Collagen is the main component in tendons and ligaments. Therefore this may accelerate the proliferative phase of tissue healing. Ultrasound is also thought to improve the extensibility of mature collagen. Thus can have a positive effect on fibrous scar tissue which forms following injury.

It is generally considered positive effects regarding tissue healing are attributed to these stated non‑thermal effects. More so than the thermal effects of ultrasound therapy.

Ultrasound Therapy And Sydney Physio Clinic

At Sydney Physio Clinic we realize that physiotherapists will develop their own style of practice as they mature as a practitioner. This will be based on influences during their training, practice and through their continuing education. These educational influences coupled with subjective and objective experiences, will dictate how treating practitioners manage their patients. Including what electrotherapy modalities of treatment, if any, they prefer to use. Physiotherapists have a number of treatment approaches at their disposal when helping their clients. Electrotherapeutic devices such as ultrasound therapy, laser and shockwave therapy make up only a small part of their treatment arsenal.

Disclaimer: This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific medical advice or assistance on Physio And Ultrasound Therapy should consult his or her general practitioner, physiotherapist, orthopaedic surgeon or otherwise appropriately skilled practitioner.