Ultrasound Therapy: How does Ultrasound Therapy work?

Ultrasound Therapy can be used in a variety of different situations, from the treatment of sprains to medication. We will tell you all about it!
Ultrasound is one of the most widely used equipment by physiotherapists. Medical professionals have been using ultrasound therapy for several years and use it to diagnose and treat a range of different conditions.

While ultrasound is perhaps more commonly used as a diagnostic tool, we will leave this use aside for today to focus on different applications of ultrasound in the field of physiotherapy.

What is Ultrasound?

Ultrasound is sound waves at a frequency that the human ear cannot hear. A sound is a form of energy in the form of waves. Sound waves cause vibrations of molecules in the air, liquid, or solids they pass through. The number of times the sound wave vibrates molecules per second is expressed in terms of frequency (Hertz). The human ear can hear sounds that cause 50 to 20,000 vibrations per second. The ultrasound waves used in physical therapy are generally between 800,000 – 3,000,000 Herz. It can be briefly expressed as 0.8 – 3 MHz (megahertz). As the ultrasound frequency increases, the transition to deep tissues decreases. For example, 1 Mhz ultrasound waves penetrate approximately 3 times deeper than 3 Mhz.

Another parameter in ultrasound therapy is the energy density expressed in watts/cm 2. The size of the ultrasound head used is affected by variables such as the size of the treatment area and energy density.

The head of the ultrasound device has a small crystal. When this crystal is exposed to an electric current, it produces rapid vibrations called piezoelectric waves. The vibrations are propagated from the head of the device to the surroundings as ultrasound waves.

How does ultrasound therapy work?

The ultrasound machine sends small vibrations or mechanical waves to the body. Although humans can only detect frequencies up to 20,000 Hz, an ultrasound machine will operate in the 1 to 3 MHz frequency range. In other words, it’s 1 to 3 million cycles per second.

This means that as patients we will not notice any effects. However, when we apply an ultrasound probe to a part of the body, it will generate waves that cause the tissues in that area to vibrate too fast. Apart from the vibrations, it will also generate heat with increased blood flow to the area. These two physical processes make ultrasound therapy very useful.

Finally, a study published in the Journal of Orthopedic Research showed that ultrasonic waves are particularly good at stimulating collagen tissue. As a result, this type of therapy usually works best for structures such as tendons, ligaments, connective tissues, and scar tissue.

Ultrasound Therapy: How does Ultrasound Therapy work?

Ultrasound therapy – methodology

Before using ultrasound, a physical therapist will first apply a layer of gel to the skin. This is because the ultrasound probe needs a conductor to penetrate the skin and reach the deeper layers of tissue. The gel is ideal for this.

It is important to constantly move the probe to avoid “beating” the same tissues for a long time. Drawing small circles allows the vibrations to spread without damaging the tissue.

The ultrasound machine can generate waves in a steady or pulsatile flow. A steady stream of ultrasonic waves creates a greater thermal effect, while a pulsatile flow helps to create a greater mechanical effect.

Benefits of Ultrasound Therapy

Ultrasound has many applications in medicine, from cleaning teeth to relieving muscle pain. In the physical therapy process, ultrasound is an effective way to treat pain and speed recovery. Here are some ways ultrasound therapy can benefit you.

  • Deep Heat – The vibrations produced by ultrasound therapy cause the affected muscles to vibrate and generate heat. This heat penetrates deeper into the muscles than hot packs that only transmit heat to the surface. Different frequencies can penetrate different depths so the therapist can precisely target specific parts of your body.
  • Deep Stretching – Tense or tense muscles are soothed by ultrasound vibrations and the heat they generate. This helps relieve muscle spasms and muscle shortening caused by the injury. Ultrasound also increases the range of motion to help muscles restore their previous performance levels.
  • Reduces Pain – Reducing muscle tension and spasm results in less pain overall. Muscles often contract when held tight for a long time; loosening them helps relieve pain. Additional therapy and treatments become significantly easier and provide faster recovery.
  • Tissue Healing – Ultrasound helps speed up the recovery rate of muscles. It provides more nutrients by stimulating blood flow to the affected area. The metabolism of local cells is stimulated by sound waves, making them more open to receiving nutrients. The vibrations help these tissues to heal faster by increasing collagen production (the main component of soft tissues such as ligaments and tendons).
  • Control of Scar Tissue – Vibrations from ultrasound reverberate in cells around the affected area. These “micro-vibrations” affect the fibers responsible for scar tissue formation and prevent scarring. Ultrasound also helps to improve the range of motion by breaking down some of the existing scar tissue.
  • Relieves Inflammation – Ultrasound is known to reduce swelling and chronic inflammation, especially in cases of muscle injury. Inflammation is a sign of muscle tension and tension, which is both painful and a possible cause of additional injury. To avoid this, ultrasound can be pulsed rather than transmitted repeatedly.

Ultrasound offers several possible treatment methods when you get help from physical therapy. In addition to soothing pain and muscle soreness, this type of therapy also speeds up the healing process.

Brampton Physiocare & Wellness Clinic offers ultrasound therapy to facilitate your recovery, along with other treatment options such as acupuncture and laser therapy.

Use of ultrasound in physiotherapy

So, in what situations can we use heat and high-frequency vibrations to treat patients? Let’s take a look at some of the situations where ultrasound therapy is commonly used.

  • Inflammation: ultrasound therapy is an effective treatment for conditions that cause inflammation. The effect of ultrasonic waves increases blood flow to the target area and supports healing. If the inflammation is no longer acute, increasing blood flow encourages the body to replace old or damaged cells. This is why ultrasound therapy can be used to treat conditions such as tendinitis, bursitis, and capsulitis, among others.
  • Sprain: As we mentioned earlier, tendons are the best ultrasound-absorbing tissue, the best treatment for injuries where the tendon is overstretched and harms good candidates for this type of treatment.
  • Healing and scarring: ultrasound therapy can also speed up the healing process by increasing cell metabolism and promoting healing.
    Currently, there is not enough scientific evidence to confirm whether ultrasound therapy is an effective treatment for musculoskeletal injuries. Although some recommend ultrasound therapy for problems such as muscle cramps, its effectiveness has not yet been proven. In any case, physiotherapists already have a range of proven treatment options to offer patients.
  • Iontophoresis: Iontophoresis therapy consists of using ultrasound to deliver medication to the patient’s subcutaneous tissue. This technique involves applying the drugs directly to the skin in gel form, resulting in better absorption, rather than applying a conductive gel to the skin. Results achieved will depend on the drugs used.

Contraindications and precautions

Because it uses high-frequency vibrations, there are some precautions you should take when using ultrasound in physiotherapy. First, an ultrasound is not suitable for use on tumors or any tissue that could cause bleeding.

Similarly, it is not recommended if the patient suffers from an infection or conditions such as deep vein thrombosis, arteriosclerosis, or similar circulatory problems. Finally, it is important to be careful when using it with patients with metal implants or pacemakers. It is important to move the probe frequently, paying particular attention to the bony areas.

Indications for ultrasound therapy

  • Arthritis
  • Osteoarthritis
  • Shoulder periarthritis
  • Myofascial pains
  • Soft tissue injuries
  • Calcified bursitis
  • Shoulder bursitis
  • Shoulder adhesive capsulitis
  • Carpal tunnel syndrome
  • Subacromial bursitis
  • Subdeltoid bursitis
  • Calcified shoulder tendinitis
  • Sprains
  • Elbow epicondylitis
  • Herpes zoster
  • Perineal lesions
  • Neuroma and Neurofibroma
  • Rheumatoid nodules and plantar fasciitis
  • Pressure ulcers
  • Venous ulcers
  • Plantar wart
  • Tenosynovitis
  • Bicipital tendonitis

Apart from these, the “trigger” points of ultrasound treatment can also be used in postpartum perineal trauma, hemiplegic painful shoulder, and frozen shoulder.

How Is Ultrasound Therapy Performed?

A physical therapy technician or physiotherapist applies a transmitting gel to the area to be ultrasound. The device is turned on and the frequency, intensity, and application time of the ultrasound waves are determined. The most suitable parameters vary according to the target tissue and disease. Then the ultrasound head is gently passed over the skin of the treated area. The Head is moved with circular or back and forth movements according to the treatment area. It doesn’t stay long in a particular place. Treatment time is usually 3-10 minutes. It is applied once a day. 15-20 sessions are continued.

For places with excessively indented protrusions such as hands and feet that do not allow full contact of the ultrasound head, the treatment can be applied in water.

During the ultrasound treatment, the person usually does not feel anything. Sometimes there may be a slight feeling of warmth and tingling in that area. If the ultrasound head is left stationary at one point without moving it, it may cause pain and tissue damage. For this reason, the head must be constantly moved.

Is Ultrasound Therapy Effective?

How effective ultrasound therapy is a controversial issue. Although there are studies that support the effectiveness of the treatment, there are also scientific publications that suggest that it does not have any benefit. Ultrasound is almost always used in combination with other methods of physical therapy and exercise.

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