Physical Therapy or Physiotherapy plays a particularly important role as the first line of treatment in pain management – for acute, subacute, or chronic pain. For decades, several modalities such as technologies in Electrical Currents, Ultrasonic, Lights and radiations (Lights & lasers) have been used. However, in the last decade, one modality that has really caught the attention of professionals in Pain Management is Shockwave Therapy Units.
Shockwave can be defined as a strong pressure wave in any elastic medium such as solid, Liquid, or Gas. Such waves can be produced & felt when you stand close to a supersonic aircraft, explosions, lightning, or other phenomena that create violent changes in pressure.
Characteristic Properties and Parameters of Shock Waves
The energy of a shockwave is released as pressure on the environment. This pressure is remarkably high, builds up extremely fast and with a classical shock wave the pressure amplitude is mainly positive pressure. The negative part is much weaker and longer and corresponds to the tension wave, hence, the key characteristics of Shockwave are: Extremely fast rise of the curve, extremely high pressure, Low negative wave compared to very high peak pressure
Extracorporeal Shock Wave Therapy (ESWT) is a conservative treatment modality with ever-growing interest in musculoskeletal disorders. Modern musculoskeletal ESWT is divided into focused and radial technology and most musculoskeletal lesions to be treated are easy to reach with either of them.
In Late 70s & early 80s, Focused shockwaves were introduced as Lithotripter technology for damaging and destructive effects on Tissue (like Kidney Stones), while these effected were desired, it was also noticed that there were regenerative physiological effects as well in the areas that received lower energies.
This led to development of a focused shockwave with positive lower energies delivered at non-destructive levels. These Focused shockwaves started to produce incredibly positive results of specific musculoskeletal conditions such as tendinopathies and in Bone healing. These devices focus the shockwaves to a point which is approximately 4–6 cm apart from the application to the skin.
FOCUSED Shockwaves (f-ESWT) are generated extra-corporeally (electrohydraulic, piezoelectric, or electromagnetic). Such energy is focused by concentrating reflectors and is transmitted inside the body to induce therapeutic effects at a target area via external applicators.
In the early 2000s, there was a further development to offer lower cost and less energy devices hence devices with ballistic pressure waves were developed – they were able to produce RADIAL Pressure waves – mechanically by a compressed air driven projectile which hits the applicator. This technology is since named radial ESWT (rESWT).
Such ballistic Radial shockwaves were generated either via Pressure generated Chamber Or electromagnetic Chamber – that controlled the movement of Projectile in a tube that Hits the end Plate with a force – that ultimately transmits to the Subcutaneous tissue. As the Energy
In contrast to f-ESWT, the maximum rESWT energy in Radial Shockwave is delivered at the applicator Tip to skin interface. Focused shockwaves peak pressure is about 100 times higher while the pulse duration is 1000 times shorter. The clinical effect of rESWT are now growing with emerging research and now being demonstrated as a widely accepted method with comparable results specifically for superficial musculoskeletal disorders.
Different tissues possess different acoustic impedance. At the interface between these tissues, acoustic energy is released and transformed into mechanical energy.
In contrast – RADIAL shockwaves have different physical characteristics. They are pressure waves and not real shockwaves.
Bio-physiological Effects of ESWT
Mechanical energy is transferred to the cell by altering the cytoskeleton and extracellular molecules connected to the cytoskeleton. It is probable that stimulus transmission occurs particularly in the cell nucleus, but also in other cellular structures (endoplasmic reticulum, mitochondria, etc.).
Neovascularisation plays a central role in the healing of ESWT-treated areas (formation of new blood vessels). This has been demonstrated with several clinical finding. In addition, changes in the nerve cells can also be detected, which would explain a change in pain perception after ESWT.
• Other key physiological effects include new functional proteins induced by ESWT promoting a chondro-protective effect, anti-inflammation, anti-apoptosis, and tissue and nerve regeneration and as well as improves the treatment of ischemic muscle.
Clinical Applications for specific conditions
Following are the list of approved clinical indications that are based on the strength of the supporting clinical evidence:
• Calcifying & Non-Calcifying tendinopathy of the shoulder
• Lateral epicondylopathy of the elbow
• Greater trochanter pain syndrome
• Patellar & Achilles tendinopathy
• Plantar fasciitis
Among recently emerging applications with available research evidence includes – Erectile Dysfunction & Bone Healing (Focused Shockwave); Knee Osteoarthritis / Myofascial dysfunction and Trigger Point therapy and back Pain management (Radial Shockwave)
Contraindications and adverse effects of ESWT
While Shockwave therapy is providing great outcomes in pain management, care has to be taken to exclude certain conditions such as – Epiphyseal plate in focus Shockwave, Coagulopathy (high-energy ESWT is associated with a risk of bleeding ), Acute infection, Lung, Brain and nerve ( in focus Shockwave ), Pregnancy, Malignant tumor in focus.
Both Focused and Radial Shockwave techniques are being used by the professionals for Pain Management. A systematic review – confirms that “there is no scientific evidence in favour of either rESWT or fESWT with respect to treatment outcome” (ref – C. Schmitz, N. B. M. Csasz´ar, S. Milz et al., British Medical Bulletin, vol. 116, no. 1, 2015)
However due to the smaller sizes and lower costs of the devices, Radial ESWT has increasingly been used all over the world. Even if the applied energy diminishes by square relative to the penetration depth, this method has demonstrated its effectiveness for soft tissue injuries and applied to treat more complex musculoskeletal symptoms associated with trigger points.
About the Author
As the Founder and Managing Director of V2U Healthcare, Dinesh Verma has established the company’s vision and mission and worked on crafting strategies to fulfil desired outcomes. He pursued part-time studies in Business Administration and later completed an MBA from Henley Management College in 1999.
Dinesh has always wanted to create a difference by being a Solution Provider and not merely a distributor of physiotherapy products. Hence, he, along with his team, emphasized on careful technology selection, invested in employee learning, and educating the customer.
To remain relevant, he established V2U’s clinical services in Physiotherapy in 2006 – Physio Asia Therapy Centre. This also provided as a test-bed for the company’s technologies and concepts.