Therapeutic Ultrasound for Muscle and Joint Pain: What It Is and Does It Work?

Quick answer: Therapeutic ultrasound is a physiotherapy treatment that sends high-frequency sound waves through the skin using a gel-covered probe. It gently warms and stimulates muscles, tendons and ligaments. It is painless and safe for most people. It works best as an add-on to exercise, not a cure on its own.

What is therapeutic ultrasound?

Therapeutic ultrasound uses the same type of sound waves as an ultrasound scan for a baby, but with different settings. A scan uses sound waves to take pictures. Therapeutic ultrasound uses them to deliver energy into your tissue.

Even though the name is ‘sound wave’, but we don’t hear it. Physiotherapists usually choose a lower frequency (1 MHz) for deeper tissues such as the hip or lower back, and a higher frequency (3 MHz) for tissues close to the skin, such as the elbow, wrist or ankle.

How does therapeutic ultrasound work?

It works in two main ways:

• Heating effect. In continuous mode, the sound waves make tissue vibrate and warm up slightly. Warmth increases blood flow, relaxes tight muscles and makes stiff tissue easier to stretch.
• Non-heating effect. In pulsed mode, the waves cause tiny movements of fluid around cells. This may stimulate cells involved in healing.

What conditions can therapeutic ultrasound help treat?

It is commonly used for:

• Tendon problems, such as tennis elbow, shoulder tendinopathy and Achilles pain
• Calcific tendinitis of the shoulder (calcium deposits in a shoulder tendon)
• Ligament sprains and muscle strains, after the first few days of injury
• Plantar fasciitis (heel pain)
• Knee osteoarthritis
• Carpal tunnel syndrome

What happens during a therapeutic ultrasound session?

• Your physiotherapist positions you comfortably, sitting or lying down.
• A cool gel is applied to the skin over the painful area.
• The therapist moves the probe slowly in small circles over the area for about 5 to 10 minutes.
• You will usually feel nothing, or only mild warmth.
• It should never hurt. If you feel heat, a deep ache or discomfort, tell your therapist immediately so the settings can be lowered. A typical course is 6 to 10 sessions, almost always combined with exercises.

Who should avoid therapeutic ultrasound?

Ultrasound should not be applied over:

• A pregnant abdomen, pelvis or lower back
• Known or suspected cancer
• An active infection
• A blood clot (deep vein thrombosis)
• The eyes, reproductive organs or a pacemaker
• Areas recently treated with radiotherapy

Your therapist should take extra care if you have:

• Reduced skin sensation (for example, from diabetes), because you may not feel overheating
• A bleeding disorder or take blood thinners
• Metal implants or a joint replacement in the area
• Open growth plates (children and teenagers)

Frequently asked questions

Is therapeutic ultrasound painful?

No. Most people feel nothing or a slight warmth. Pain or a deep ache means the setting is too strong, so tell your therapist.

Is therapeutic ultrasound the same as an ultrasound scan?

No. Both use sound waves, but a scan creates images to diagnose a problem. Therapeutic ultrasound delivers energy to treat tissue.

How many sessions of ultrasound therapy do I need?

Usually 6 to 10 sessions over 2 to 4 weeks. If you see no improvement after 4 to 6 sessions, discuss other options with your doctor.

Can ultrasound therapy break down scar tissue?

There is no strong evidence that it breaks down scar tissue. Gradual stretching and loading exercises are more effective for this.

Can I buy a home ultrasound therapy device?

You can, but they are often low-powered and easy to use incorrectly. Given the modest evidence, your money is usually better spent on a guided exercise programme.