Ultrasound Therapy in Physiotherapy

“It’s a boy!” or “It’s a girl!” Many of you will be familiar with images of the foetus peeking out on the small monitor when the excited gynecologist proudly announces the sex of the baby to the expecting parents.

This is the typical and more familiar use of ultrasound that we associate with, scanning the deeper realms of the human body, revealing its secrets. What you may not know is that ultrasound technology is also commonly used in physiotherapy for treatment of muscles, ligament injuries. Recent research has shown that it can make broken bones heal faster!

What is ultrasound?

As the name implies, ultrasound machines produce sound waves that have been found to have healing effect on muscles, ligaments and bones. These sound waves are ultrasonic, beyond the upper limit of human hearing and the 2 most commonly used frequencies of the sound waves are 1MHz (megahertz) and 3MHz. These waves travel through the skin and get absorbed by the soft tissues and bones.

How does it help in healing then?

For soft tissues such as muscles and ligaments, there are basically 2 ways the ultrasound is proposed to work, thermal (heating effect) and non thermal (non heating effect).

High intensity continuous ultrasound can cause the tissues to have a heating effect. This heating effect causes the surrounding blood vessels to expand, improving the blood circulation to that area. The heat also increases the metabolic rate of the cells othe soft tissue, increasing its healing capability.

On the other hand, when there is acute injury to the soft tissue or bone, the heating effect can cause an adverse reaction instead. In this instance, low intensity pulsed ultrasound is preferred. This low intensity, pulsed ultrasonic waves increases the cellular activity of the injured soft tissue and thus promoting a faster healing, without the detrimental effects of heating.

I felt nothing during the treatment, does it really work?

During the treatment, you will not feel much though. The most that you will feel during a session is mild warmth.

Evidence for Ultrasound

As for the efficacy of ultrasound therapy in the healing of soft tissues, there is unfortunately no conclusive consensus on its therapeutic effects.
Current research suggests that effective evidence based application of ultrasound is highly dependent on therapist knowledge and appropriate training in ultrasound application.
It remains a popular choice for physiotherapists mainly due to its clinical effectiveness reported by many clients.

Strong Evidence for use of ultrasound in fracture healing

Despite the inconclusive effects of ultrasound on soft tissue healing, there is very strong evidence in recent research to show that low intensity, pulsed ultrasound, started seven days after a diagnosed fracture of the bone, applied daily for one time of 20 minutes each time, can induce healing of the bones and reduces the healing time by 20-40%.

Should you wish to find out more about ultrasound and how It may help you, please feel free to get in touch

References
1. Nussbaum, E.L. (1997). Ultrasound: To heat or not to heat-that is the question. Physical Therapy Review, 2, 59-72.
2. Watson, T. (2008). Ultrasound in contemporary physiotherapy practice. Ultrasonics, 48, 321-329.
3. Dyson, M. (1987). Mechanisms involved in therapeutic ultrasound. Physiotherapy, 73(3), 116-120.
4. Heckman et al. (1994). Acceleration of tibial fracture0healing by non-invasive, low intensity, pulsed ultrasound. The journal of Bone and Joint Surgery Am, 76:26-34.