You fall, you twist and injure your leg, you’ve been feeling a pain on the foot that just doesn’t seem to go away AND you’re afraid of surgery? What other options are there? In the world of modern science and treatment for sports injuries, there are a plethora of viable alternatives, ranging from traditional RICE – Rest it, Ice it, Compress it, and Elevate it to minimally invasive surgical techniques to long-term physiotherapy…the list goes on and on…Extracorporeal Shock Wave Therapy (ESWT) is just one of them…but what is it exactly?

In this article, we aim to explain ESWT, who is eligible for it, and the outcomes you would expect from it. We will also discuss remarks by people who have used it and found it helpful.

What is extracorporeal shock wave therapy?

It is a form of shockwave treatment, where a device that generates pressure waves is used to generate healthy tissue growth or stimulate recovery. The concept first originated from Extracorporeal Shock Wave Lithotripsy, a treatment method used to break down small kidney stones into even smaller ones so that they can pass through the front passage easily.⁷

ESWT started randomly when there was a response of bone cells when it was tested on animals in the 90’s, fast forward to the present day. It has become one of the leading choices of treatment for musculoskeletal conditions.

Extracorporeal shock wave therapy is non-invasive, producing more or less focused pressure, as needed, in the form of shockwaves directly onto the skin superficially. The effects of these shockwaves are 1000 times more than ultrasound. This treatment can be aimed at all biological levels- cellular, tissue and organ.^12,13

The use of it in sports injuries can be through:

• Aiding the formation of new blood vessels (neovascularization) at the joints and tendon-bone areas
• Altering the structure of tissue growth and development to accelerate healing
• Increase the amounts of inflammatory and “recovery” type cells to promote healing
• Stimulating the growth of joint and tendon cells

The use of this method of treatment is gaining a lot of applause from the medical community for chronic muscle injuries, new musculoskeletal problems, and sports injuries. It is seen as a safe treatment method that reaps benefits faster than traditional approaches.⁹

How does it work?

The complete mechanism isn’t yet fully understood but there are two types of shockwaves used,³

• Focused shockwave: this type uses Electrohydraulic, electromagnetic and piezoelectric devices. These devices can use higher energy, and can reach tissues deeply but can be quite painful to use at the time of application¹⁰
• Radial shockwave: this type uses Pneumatic or Ballistic devices and produces lower energy. Again, the energy can reach deeply at selected superficial points, at the time of application the high energy can be painful whereas lower energy will be less painful

Essentially these shockwaves put out a positive pressure that promotes healing. As mentioned before it works on all levels. For instance, at a cellular level, a protein called “adenosine triphosphate” which is primarily involved in being a source of energy, storing and activating cell signalling pathways is released, this causes a cascade of events that eventually leads to biological healing by enhancing blood flow, metabolism regrowth and healing of bones and surrounding tissues.⁴

A small handheld device is used to directly apply the shockwaves onto the skin, it can target a wide or small range, usually up to 6 cm of tissue can be reached.1 The aim is to be more reliant and effective than commercial massage applicators or percussion therapy devices. Some people have reported pain and discomfort for a short while and some areas of the body can certainly be more sensitive than the rest; however, the discomfort is temporary. The complete treatment process can take from a few weeks to a few months and the people report an elevation of pain almost immediately.

 Common sports injuries treated with ESWT

• Proximal plantar fasciitis of the heel: This is when there is a pain of varying intensities at the heel of the foot. There is no specific time of the day that the pain intensifies but the pain usually subsides after a few minutes of movement. It is an injury that occurs because of overusing the foot that causes damage to the tissue in the foot. ESWT will work on healing the overworked tissue and reduce the pain by targeting specific areas
• Greater trochanteric pain syndrome: This is a condition where there is pain at the side of the hip during the passive and active movement. It may be caused by increased use of the hip tissues through exercise, sitting for lengths at a time, climbing stairs and standing for long periods of time
• Proximal hamstring tendinopathy: This condition is usually associated with athletes who take part in the long-distance races, sprinting or hurdles. This condition causes a lot of pain causing subpar performance, limited range of movement and discomfort
• Lateral epicondylitis of the elbow: This is a condition when the tendons (structure that connects the bone to muscles) surrounding the elbow bend the wrist backwards and causes the wrist to move away from the palm. This results in pain and discomfort, usually due to the overuse of the tendons. This condition is often called ‘Tennis Elbow’ because it is often seen in tennis players. ESWT works here by creating an inflammatory reaction and degradation of the nerve bundle, this reduces the pain
• Non-union of a long bone fracture: This is a condition when a fracture that has previously occurred in a long bone has not healed appropriately. These commonly include the bones of the arm, bones of the legs and thighs and rarely the clavicle. The healing process has come to a halt and causes pain, discomfort and sometimes irritation
• Patellar tendinopathy: This occurs as a result of stress to the tendons in the knee, it can be painful and greatly uncomfortable. It is a common sports injury. ESWT will increase the elasticity of the muscle and tone of the muscle
• Calcific tendinitis of the shoulder (rotator cuff tendinopathy): when there’s a build-up of ‘calcium phosphate’ in your muscles or tendons of the shoulder, this condition occurs causing a lot of pain and limitation in the range of movement of the shoulders. ESWT will induce an increase in tendon cells, reduce the pain and numbness of the shoulder⁸
• Achilles tendinopathy: a lot of runners have a varying degree of this condition, which occurs due to the overuse of the Achilles tendon on the foot. It is a chronic condition and is associated with low-intensity pain and difficulty in movement, due to stiffness of the foot. ESWT focuses on repairing and regenerating the new cells to reduce pain in the tendon. It aims to break down scar tissue
• Avascular necrosis of the femoral head: this condition can happen following a lot of predisposing factors; for example- previous fractures, radiation treatment and use of alcohol. It is when the head of the thigh bone “dies” or deteriorates due to an interruption to the blood supply to it. This results in a lot of pain and extreme discomfort and limited range of motion. It is common in older persons

Along with these specific conditions muscle strains, ligament strains, small stress fractures and shin splints are also treated by ESWT.^5,6,11

Clinical efficacy, benefits, when to and when not to, advantages and disadvantages

Usually, ESWT is tried in patients who have not responded to the traditional methods. Most patients react positively to the treatment, however there are a few cases of side effects reported. The most common side effect is pain during the treatment itself, then due to high energies used in treatment, the skin can break out and have some associated minor bleeding or reddening of the skin.

It has proven to be a good, safe treatment option that helps athletes recover faster and get back into routine within a few weeks. It is a viable option for in-season athletes because of the time taken for recovery. It is theorized that the effects of ESWT can be optimized if used in parallel to physical therapy as opposed to being a single form of treatment.² ESWT is tolerated well by young people and this can be a great advantage because younger muscles and tissue heal faster than older people because of their metabolism and regenerative hormones.

The disadvantages of this procedure is that the literature surrounding the subject is still very amateur and long-term rehabilitation programmes and research investigations need to be done to have a more solid foundation on ESWT. If the energy levels are high it can cause distress and discomfort in the patient and should especially be avoided in pregnant mothers and older sportsmen over 40.

In summary, the majority of the people who have undergone extracorporeal shockwave therapy have reported immediate relief and speedier recovery in an estimate of 5-6 sessions over the course of 8-12 weeks. Most athletes were able to return to their previously performed physical activity without any hindrance.