Introduction

Most people experience back pain at some point in their lives, although for some individuals it is a regular problem. Numerous factors can trigger back pain, making it difficult for people to work, move around and enjoy their daily activities. People these days are turning to ultrasound therapy as a treatment option because it provides a safe, non-invasive solution to their back pain. The treatment uses sound waves to achieve pain relief and promote healing processes. In this article, we will delve into how ultrasound therapy helps with back pain.

What is ultrasound therapy?

Ultrasound therapy is a treatment that uses sound waves, but at a level far too high for our ears to pick up. The machine basically sends out very fast vibrations (around millions every second), which is far beyond what we can hear. It isn’t just used for back pain: it is also helpful for sprains, tendon problems, arthritis, sore joints, and even old scar tissue that causes aches.¹ 

How does ultrasound therapy work?

A small probe is pressed against the skin to send sound waves into the body. Before doing this, however, a layer of gel is placed on the skin. This gel is important because it allows the sound waves to travel easily from the machine into the body. Without the gel, the sound waves would just reflect off the skin's surface.

Do you know why ultrasound therapy is applied to muscle, tendon, and joint issues? It is because ultrasound waves propagate more easily through protein-rich tissues such as tendons, ligaments, and scar tissue.^1,2

Thermal and non-thermal effects of ultrasound therapy

The vibrations created by ultrasound are transmitted into the tissues below the skin to create energy. This energy can either generate heat within the tissues or cause other physical effects. Both effects normally appear together and are described below:

Thermal effects

• The sound waves create vibrations, which create heat in tissues
• This heat increases blood flow, relaxes tense muscles and tissues, and promotes rapid recovery
• Supplying heat to ligaments and tendons makes them more pliable and facilitates movement²

Non-thermal effects

• Sound waves can create small bubbles within the tissues that expand and collapse, a phenomenon known as cavitation
• These bubbles also induce movement of fluid within the tissues, referred to as microstreaming
• Both these effects have a microscopic massaging effect that decreases inflammation and supports tissue healing^2,3

Types of ultrasound therapy

• Continuous ultrasound: the sound waves are released slowly over the course of the session, and this is typically performed when the goal is to generate heat in the tissues
• Pulsed ultrasound: the sound waves are released in pulses, which generate non-thermal effects⁴

The therapist may also adjust settings such as:

• Frequency: 1 MHz for deeper tissues (like muscles), and 3 MHz for superficial tissues (such as tendons closer to the skin)
• Intensity and duration: adjusted based on the condition being addressed

LICUS: a modern advancement

Low-intensity continuous ultrasound (LICUS) is a newer form of ultrasound therapy that can be used at home. In contrast to ultrasound treatments in a clinic that are brief, lasting between 5-15 minutes and delivering a limited dose of energy, LICUS machines can be applied for up to four hours a day, safely delivering a much greater amount of energy.

The gentle heat, given in this manner, warms the muscles and tissues slowly and avoids shocking them or causing damage. It also relieves painful muscle knots (trigger points) and even supports bone healing.^2,5

Key benefits of ultrasound therapy for back pain

• Enhances circulation: the heat produced by ultrasound enhances blood flow, increases oxygen and nutrient supply to the damaged area, and accelerates healing
• Relaxes stiff muscles: the warming effect decreases spasms and tightness in the muscles
• Makes tissues more flexible: heat softens connective tissues such as tendons and ligaments, making them more flexible, which enhances movement and decreases stiffness in the back
• Decreases inflammation: one of the main advantages of the treatment is a reduction in swelling and inflammation³
• Aids healing at the cellular level: microscopic vibrations act like a gentle massage, enhancing cell function and repairing tissues³
• Switches off muscle knots (trigger points): LICUS in particular, assists with muscle knots in the back muscles⁵

Advantages of ultrasound therapy

• No surgery, needles, or cuts required (non-invasive)
• Safe, with extremely few side effects being reported
• Cost-effective in the long run, as it minimises the need for continuous medicines or clinic visits
• It can be used along with exercises and medication for an improved outcome
• Treatments such as LICUS (low-intensity continuous ultrasound) can offer consistent and constant pain relief 
• Reduces reliance on painkillers, which can be toxic in the long term and expensive over time
• Enhances movement, comfort, and general well-being in individuals suffering from chronic pain

Safety and side effects

Ultrasound therapy is generally very safe, and side effects are uncommon. However, it should always be supervised by a trained physiotherapist or medical practitioner.⁵

Limitations and considerations

Although most patients experience considerable relief, ultrasound therapy is not a cure. Its effectiveness varies based on the cause of the pain. It works better for soft tissue injuries, such as strains and tendon problems, compared to severe spinal problems. 

It might not be suitable for everyone, and some individuals may not get sufficient relief from ultrasound alone, so it is generally prescribed as part of an overall treatment plan, which may include medication, exercise, and other forms of therapy.

What to expect during a session

A typical ultrasound session lasts for about 5–10 minutes:

• The therapist applies gel to the skin
• A handheld probe is moved over the region experiencing pain
• Sound waves penetrate deep within the tissues, producing the thermal and non-thermal effects discussed earlier 

Most people may require several sessions, depending on the severity of the condition.²

Summary

Most people experience back pain at some point, and for some, it is a frequent issue. Ultrasound therapy has emerged as a safe, non-invasive treatment option that uses sound waves to relieve pain and promote healing. The therapy involves a small probe that sends fast vibrations into the body through a layer of gel applied to the skin, which allows for better sound wave transmission. Ultrasound therapy has both thermal and non-thermal effects. Thermal effects include increased blood flow and muscle relaxation, while non-thermal effects involve creating small bubbles in tissues that help reduce inflammation and support healing. There are two types of ultrasound therapy: continuous, which generates heat, and pulsed, which produces non-thermal effects. A newer form, low-intensity continuous ultrasound (LICUS), can be used at home and safely delivers energy over extended periods, aiding muscle relaxation and healing. Key benefits of ultrasound therapy include enhanced circulation, reduced muscle stiffness, decreased inflammation, and improved cell function. While generally safe, ultrasound therapy should be guided by professionals and may be part of a broader treatment plan, as it may not work for everyone or every cause of pain. Sessions last about 5-10 minutes and often require multiple visits for effectiveness.

FAQs

Is ultrasound therapy the same as the one used in pregnancy scans?

No. Ultrasound imaging (such as pregnancy scans) uses sound waves to produce images. Therapeutic ultrasound, on the other hand, projects sound waves into the tissues to alleviate pain and aid healing.

Is ultrasound treatment painful?

No. The treatment is painless. A few individuals feel a little warmth or mild tingling, while others feel nothing.

How long is one session?

One session is usually 5–10 minutes long. Patients need multiple sessions per week over several weeks to achieve optimal outcomes.

How quickly will I feel relief?

Relief occurs after several sessions in some patients, while in others it may take several weeks. The timeline varies depending on the condition and its severity.

Is ultrasound therapy safe?

Yes. It is usually extremely safe when done by a trained professional. Side effects are extremely rare but can include mild skin irritation if used improperly.

Who should not have ultrasound therapy?

It may not be appropriate for individuals who have any growths or tumours, open wounds, infections, or pregnant women when applied to the lower back or abdomen. Always check with your doctor first.

Can I use ultrasound therapy at home?

Yes. More recent models, such as LICUS (Low-Intensity Continuous Ultrasound), are safe to use at home and can deliver longer, sustained pain relief.

Can ultrasound therapy be a substitute for medicines?

It might reduce the need for repeated administration of painkillers, but it tends to work best within a comprehensive treatment regimen that might incorporate exercise, stretching, or other treatments.

What types of back pain are best treated by ultrasound therapy?

It is most effective for soft tissue injuries such as muscle strains, tendon problems, and muscle knots. It might be of less benefit for serious spine issues.

Who do I see to receive ultrasound therapy for the treatment of back pain?

Ultrasound therapy is most widely used by physiotherapists, but is also offered by other healthcare professionals, including chiropractors, osteopaths, and sports therapists.