Extracorporeal Shockwave Therapy (ESWT)

By Glenn Cameron, Innovative Therapy Canada

Shockwave therapy is the therapeutic application of highly specialized acoustic (sound) waves used to break apart various types of hardened unwanted dysfunction responsible for pain and immobility in muscles, tendons, or joints.

Many shockwave therapy devices exist in the world but vary in their capability to solve problems. The practitioner must choose the appropriate device best suited for their practice and the types of conditions they intend to solve with its use.

The success of any shockwave therapy treatments depends on the skill and experience of the practitioner, and on the capability of the device being used.

Definition: What are Shockwaves?

Shockwaves are a unique type of pressure waves, abruptly alternating from a high pressure to a low pressure, faster than the speed of sound. They are created within the soft tissues of the body, by the application of highly specialized acoustic waves from a shockwave device. Shockwaves are used in modern medicine as an alternative to surgery for specific conditions that cause pain. Shockwaves are not electrical in nature as their name may imply. They are also not to be confused with other acoustic wave technology such as ultrasound, TENS, IFC or muscle stimulators.

Two major differences exist that distinguish shockwaves from ordinary pressure waves.

Shockwaves travel faster than the conventional sound wave, faster than the speed of sound (shock) at 760 miles per hour.

Secondly, shockwaves possess a high degree of energy as seen in physics, meaning they possess the ability to do work when applied to the tissues in the body. The work which shockwaves are known for, is their ability to break apart unwanted structures in the body which ultimately cause pain.

Shockwaves are used in medicine to break apart kidney stones in a process called Lithotripsy. Therapists also use shockwaves to break apart unwanted calcium deposits and the hardened, twisted/tangled bands (myofascial adhesions) which develop in muscles, tendons, and ligaments, responsible for so many painful conditions. The term “Dysfunctions” refers to any abnormal tissues in the body, including adhesions and the calcium deposits which can invade them.

Brief History of Shockwaves

Shockwaves were first discovered during the second world war when the U.S. military was testing depth charges used to sink enemy submarines. Swimmers at a nearby beach noticed odd sensations on their body, But couldn’t identify what they were experiencing. They were experiencing shockwaves created when the depth charges exploded deep under water, many miles away.

It wasn’t until the 1980’s when shockwave technology was perfected for use in breaking apart kidney stones, and in the hands of therapists by the late 1990’s. 

Types of Shockwaves: Radial vs Focused

Radial shockwaves disperse in a radial (round) pattern, increasing in the diameter and depth as they travel deeper into the soft tissues of the body. They are preferred to resolve larger regions of dysfunction in muscles, tendons or ligaments.

Focused shockwaves do not disperse, but rather remain in a narrow beam pattern. Focused shockwaves are ideal for small, extremely dense dysfunctions such as chronic tendonitis and heel spurs. These shockwaves require extreme skill from the therapist as an incorrect application angle of the shockwave beam could miss the targeted tissues, resulting in a totally ineffective treatment. Both have their advantages and disadvantages in treating conditions, to be chosen by the therapist based on the condition being treated.

The success of any shockwave therapy treatment directly depends on the knowledge and skill of the therapist, as well as with the quality of shockwave unit being used.

How Shockwaves Work

Each acoustic wave from a shockwave unit has a leading edge called a “wavefront”, where its energy (ability to do work) is located. This potential energy comes from the pressure used to create the shockwaves, and from the applicator that disperses them. The most powerful shockwaves available to therapists are generated at 90 pounds per square inch (PSI).

The ability for shockwaves to push their way into the body, and specifically into dysfunctional tissue, comes from this high energy wavefront. The more energy a shockwave possesses, the more capable its wavefronts will be penetrating dysfunctions. There are times when some basic shockwave units do not possess sufficient power to get the job done, but the higher power offered by professional shockwave units can, but makes treatments more expensive.

Here’s how the process works:

  • Acoustic waves begin entering the body when the gun-like applicator is depressed against the skin.
  • The high speed of these acoustic waves traveling faster than 760 miles per hour, cause the gases within the blood and lymphatic fluids to rapidly expand to many times their original size.
  • These rapidly expanding gas molecules cause increased pressure on the dysfunctional tissues, creating cavities or hollow voids, in a process termed “cavitation”.
  • Voids have low pressure within them, so quickly collapse on themselves or implode as rapid as they were created, thus generating an implosion wave (shockwave) of force on the tissue. Think of the process as stretching out an elastic (creating the void), then releasing it (implosion). This imploding wave force is the actual shockwave.
  • Millions of these imploding voids create a moving wave of shockwaves which travels through the entire dysfunction.
  • These shockwaves are sufficiently disruptive to cause dysfunctions to break apart.

Shockwave devices can be thought of as the acoustic wave generators which cause the cavitational process to occur, not as a device which delivers shockwaves into the body. Shockwaves can only be created in the body from the cavitational process.

The Effects of Shockwaves on Dysfunctions

Cavitation occurs only when the shockwave unit delivers its acoustic waves into the body.

Healthy muscles, tendons, and ligaments are not affected by the shockwaves created by the imploding voids. They easily absorb the forces.

Myofascial adhesions, which are the twisted/tangled, hardened fibrotic bands within muscle, tendon, and ligaments, can’t withstand the shockwave’s forces. Constant shockwave action begins breaking apart the bands, stretching the affected fibres, and allowing fresh blood to invade regions where normal circulation was absent. Painful chemical irritants which are the waste bi-products of cellular metabolism are released from the dysfunctions, causing an immediate reduction of pain.

Calcium deposits are broken apart into their molecular particles and removed from the site through the lymphatic circulation. They are further chemically degraded into their chemical molecules to be returned to the bones for storage. The calcium is recycled.

Painful inflammation is quickly eliminated from the region by the extremely high pressures created by the expansion of the gases to many times their original size, and by the wave action created by shockwaves traveling through the tissues.

Shockwaves have no adverse effects on bones, as they simply bounce off them.

Shockwaves have no adverse effects on nerve fibres, as they can easily withstand the cavitational forces exerted on them.

Shockwave Therapy: The Painful Conditions It Resolves:

  • Calcific tendonitis
  • Bunions & Hammer Toes
  • Heel Spurs
  • Arthritis
  • Tendonitis
  • Ligament Sprain
  • Nerve Compression Syndrome
  • Back Pain and Sciatica
  • Carpal Tunnel Syndrome
  • Bursitis
  • Whiplash
  • TMJ
  • Tenosynovitis
  • Osgood Schlatters Syndrome
  • Patellofemoral Syndrome
  • Plantar Fasciitis
  • Haglund’s Deformity (Pump Bump)
  • Morton’s Neuroma
  • Chronic Constipation (neurogenic)
  • Chronic Urinary Tract Infections (UTI) (neurogenic)
  • Pudendal Neuralgia
  • Adhesive Capsulitis
  • Back Pain
  • Degenerative Disc Disease
  • Frozen shoulder
  • Headaches
  • Iliotibial (ITB) Band Contracture
  • Post-Joint Replacement Scar tissue
  • Prostatitis (Neurogenic)
  • Sciatica
  • Shin Splints
  • Shoulder Dislocation
  • Shoulder Impingement
  • Shoulder Separation
  • Swelling/Edema
  • Tarsal Tunnel Syndrome
  • Tarsalgia
  • Tendonosis
  • Thoracic Outlet Syndrome
  • Trigger Finger


Back to top