Monday, November 4, 2013

Acoustic ShockWave Therapy FAQ

Accoustic ShockWave - Therapy FAQ 

Collingwood Chiropractic Clinic

What is Acoustic ShockWave Therapy?

  • The terminology for this type of therapy is emerging, however, the more recognized name in the industry is  Extracorporeal Radial Shock Wave Therapy, (or ERSWT or ESWT).  
  • "Extra-corporeal" means "outside the body" and refers to the fact that the shockwaves are generated outside the body.   
  • Radial denotes that the manner that the sound wave is transmitted from the application device through the tissue.
  • A shockwave is an intense, but very short energy wave, generated at or near the speed of sound.   
  • Acoustic ShockWave is a brand name derived to identify that the therapy uses sound waves or sound impulses or sound "shocks" rather than electrical shocks. Acoustic Shockwave and SWT may be used interchangeably in this document.
What is Shockwave Biosurgery?

  • People researching extracorporeal shockwave therapy may come across the term "biosurgery," Biosurgery is term used more commonly in Europe to denote the use of an instrument in application to perform a therapeutic procedure.
  • SWT is not surgery as the word is usually defined or understood in North America, which commonly denotes invasive treatment of injuries or disorders of the body by incision.
  • ShockWave Therapy can be use in some cases to avoid invasive surgical procedures for relief of unremitting tendonitis and contracture, and can accelerate healing of surgical interventions. Please refer to:

What is the origin of SWT?

  • The basic science behind ESWT is analogous to lithotripsy, the technology that uses acoustic shockwaves to break up kidney stones without surgery.  The technique of using shockwaves to break up kidney stones has been around for a nearly a quarter century now, and in the process of treating thousands and thousands of patients, it was found that many people undergoing the procedure had other unrelated aches and pains disappear.  It was at this point that scientists began to consider that shockwaves may have an effect to heal other sorts of tissues.  
  • Specialized machines were then developed specifically with the idea of using these shockwaves on other parts of the body, and this is the origin of SWT. 
  • The type of shockwave therapy we use, then, is specialized to specifically help treat musculoskeletal conditions. 

What conditions can you treat with Acoustic SWT?

  • Acoustic ShockWave Therapy can be used to treat a wide variety of musculoskeletal conditions--particularly those involving where major connective tissues attach to bone. 
  • Complaints involving attachment points for tendons and ligaments in major joints like the shoulder (such as the rotator cuff), elbow (epicondylitis or tennis elbow), hip, and knee (tendonitis or "jumper's knee) are common sites for ESWT. 
  • One of the areas most frequently treated with ESWT, however, is the foot.  Some conditions in the foot that have been treated with ESWT include:
    • Plantar Fasciitis or Fasciosis (Strained Arch)
      Achilles Tendinitis or Tendinosis
      Calcific Tendinitis or Tendinosis
      Connective Tissue Pain and degeneration
      Muscle Pain and Injuries
      Joint Injuries
      Morton's Neuromas
  • SWT encourages bone healing, it has been used to help treat:
    • Stress Fractures
    • Avascular Necrosis (A dead portion of bone)
    • Slow-healing bone (Delayed unions)
    • Non-healing bone (Non-unions)
  • There are also urological conditions that respond to SWT, such as Peyronie's Disease.
  • Research presented at the 2005 International Conference on ESWT in Vienna and the 2006 International Conference in Rio de Janeiro demonstrated that SWT is also being studied for use for a wide variety of other conditions as disparate as skin ulcers and other chronic dermatological lesions, infections, angina, arthritis, reflex sympathetic dystrophy (RSD), and certain neurological conditions.
  •  Many traditional therapies--such as anti-inflammatory medications, steroid injections, physiotherapy, massage, acupuncture, and so forth--can assist the body during the early, acute phase of an injury.  However, they are much less effective in assisting the body to heal when an injury becomes chronic.  As an example, many patients can relate to a history where a steroid injection (like cortisone) seemed to be effective in resolving pain early in their healing process, but subsequent injections were much less effective.  This isn't really surprising when you realize that a chronic-state, degenerative injury isn't likely to respond well to a medication designed to affect an acute-phase, inflammatory condition.
  • What makes SWT unique is that it is one of the very few technologies in any field of medicine that seems to work best when an injury reaches the chronic, non-healing state.  SWT appears to be able to jump start the healing process in chronic, non-healing injuries and move them back into the acute phase of healing.

When is SWT considered as a treatment for other conditions?

Shock Wave Therapy is may be considered when the following criteria are met:
  • When patient has a diagnosis that is considered to be potentially responsive to SWT.
  • When simpler and less expensive treatment alternatives have failed or aren't appropriate for some reason.
  • When appropriate, as an alternative to unpleasant side effects of ongoing medication.
  • When appropriate, as an alternative to surgery or other more invasive treatments.
  • Where surgery has been unsuccessful in relieving a condition.
  • When the patient fully understands the procedure.
  • When there are no known contraindications to the procedure.

When can't you use ESWT? 

  • SWT is not typically used in the presence of bone tumours, certain metabolic bone conditions, and certain nerve or circulation disorders. 
  • SWT is not typically used in pregnant patients. Certainly SWT would be avoided where it might directly impact the abdomen. However, even where a therapy might be applied to an arm or leg, due to liability issues, therapies are generally avoided unless they are proven to be safe with respect to pregnancy.
  • Locations of an open growth plate. Children and teens where the bone is still growing
  • It's not currently used in areas where an infection is present, (though there is some early research suggesting SWT may actually help with infection). 
  • It also should not be used in conditions or locations where gas or air is present in the body over the lungs or abdominal organs - rare in the locations where SWT is typically used - or for other conditions as determined by your doctor.
  • Not over the head or throat.
  • With caution directly over the spine. 

How effective is Focused SWT?

  • The answer to this question depends upon which study you read, what methods were used in the study, how "success" is measured in the study, the patients selected to be included in the study, the condition being treated, and the machine being used. 
  • As with any new technology and technique, it takes time to generate a body of knowledge to support and qualify the uses and limitations of the therapy. To state that research does not support the efficacy of a treatment is not synonymous with saying that research has proven a therapy to be ineffective.
  • The vast majority of recent studies support that shockwave is highly effective. 
    • For example, over 70 studies were presented at the 2006 international shockwave seminar in Brazil, and over 80 were presented the year before in Vienna--and this doesn't even include the numerous published findings in the medical literature. 
  • Assuming you have an injury appropriate to extra-corporeal shockwave technology treatment, most recent independent studies suggest somewhere between a 65% and a 95% "success" range, with values around 80% confidence being the most commonly cited number.  And it's important to note that most of these studies have success rates as determined by the patient, himself, in terms of pain and function.
The most important factor in getting a good result with ESWT appears to be in selecting appropriate patients most likely to benefit from this technology.  However, we can't predict which patients will respond successfully to ESWT and which ones won't.

How fast does SWT work?

  • We find that many patients get an initial degree of improvement almost immediately following treatment.  This effect is usually (but not always) temporary, and is associated with an anesthesia effect from the hyperstimulation of the tissue from the ESWT. 
  • It takes several days for injuries to begin to heal, and many patients see an improvement before the end of the second week.  Depending upon your diagnosis, the healing process may take several weeks or even months to be completed, but pain relief often precedes the completion of the healing process. 

How safe is SWT?

  • The basic technology involved with extracorporeal shockwave technology has been used for decades now on quite literally millions of people.  The technology has been used most extensively in Europe, particularly the German-speaking countries, where this technology originates.  In all its use, SWT of the musculoskeletal system has been found to have virtually no serious side-effects.  In fact, even mild side effects like tingling, aching, redness, or bruising are relatively rare, modest and short-lived. 
  • Furthermore, effects such as these appear to be more common with higher energy treatments, particularly those from earlier generations of SWT technology than that which we use.

Does SWT hurt?  

  • Protocols have been researched and establish for many applications. Treatments are generally well tolerated. Clinicians are finding they can successfully and safely use higher intensities to promote faster healing. The idea is to take as much as you can within your tolerance. There may be some sensation of pain, described as a “ping” if the sound head is held over a boney area. However, if there is any objectionable sensation, it is simply a matter of reducing the intensity to within the acceptance of the patient.
  • There may be some redness and soreness of the skin over the treatment area.
  • There may be some aggravation of pain in the area treated, akin to going exercising at the gym. Such effects are temporary and are easily managed by applying cold compresses or off the shelf medications (nsaids).
  • In short, SWT may annoy or induce local temporarily aggravation, but will not cause long term aggravation or harm.

How does SWT work?

  • Simply put, extracorporeal shockwaves stimulate certain components within the body so the body is able to heal.  And SWT is able to accomplish this even in chronic cases, when the body has demonstrated a previous unwillingness or inability to do so by itself.
  • In addition to stimulating the healing process, SWT seems to have a direct effect on nerves, diminishing pain. 

How do the physics of ESWT promote tissue healing?

  • While investigations are still being conducted to more fully understand the precise mechanism behind SWT's effects on injured tissues, the picture is becoming much clearer. 
  • Pattern of typical sound waves
    Pattern of Acoustic ShockWaves
  • SWT produces a very strong energy pulse for a very short length of time. It is somewhat akin to a vertical wall of sound energy compared to the rise and fall of a wave of sound energy.
  • This shockwave exerts a mechanical pressure and tension force on the afflicted tissue.  This has been shown to create an increase in cell membrane permeability, thereby increasing microscopic circulation to the tissues and the metabolism within the treated tissues, both of which promote healing and subsequent dissolution of pathological calcific deposits.
  • The SWT shock waves pressure front creates behind it what are known as "cavitation bubbles". Cavitation bubbles are simply small empty cavities created behind an energy front.  They tend to expand to a maximum size, then collapse, much like a bubble popping.  As these bubbles burst, a resultant force is created.  In the human body, this force is strong enough to help break down pathological deposits of calcification in soft tissues.
  • As cavitation bubbles collapse, they create smaller, secondary energy waves known as microjets.  These microjets also release energy that also breaks down pathological deposits of calcification in the soft tissues through direct, mechanical means. This phenomenon is repeated and cummulative for each individual shockwave. A typical treatment may involve 6,000 impulses. A typical therapy program includes a minimum of three treatment sessions.
  • SWT has been shown to stimulate osteoblasts, bone cells responsible for bone healing and new bone production, enhances the healing process of bone.
  • SWT shockwaves have also been shown to stimulate fibroblasts, the cells responsible for the healing of connective tissues such as tendon, ligaments, and fasica.
  • SWT initially diminishes pain through what is known as hyperstimulation anesthesia.  This is where the nerves sending signals of pain to the brain are stimulated so much that their activity diminishes, thereby decreasing or eliminating pain. This effect is usually, (but not always), short lived. 
  • Over longer periods of time, SWT stimulation activates the "gate-control" mechanism, where nerves can be stimulated to "close the gate" to pain impulses sent to the brain.  It is akin to activating a "reset" mechanism that recalibrates pain perception.
  • The effects of shockwaves are best documented in areas of changes in tissue density, such as where tendon attaches to bone (enthesiopathies) and where bone attaches to ligaments (desmopathies).  These are also regions of the body where vascularization is minimal and healing is often difficult. For this reason, it is very effective for painful connective tissue pain in such locations as the foot, knee, hip, elbow, and shoulder.

For more information, or to discuss if Acoustic ShockWave Therapy is appropriate for you, please contact me at

Dr. Wayne Coghlan, At your service.


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