Shockwave Therapy
Physical therapy is a movement and function based science and we often work with people who are injured, ill, or are managing conditions that affect their overall ability to perform daily tasks. Physical therapists often describe having a toolbox filled with tools. We select which tool to use based on a person’s presentation and unique condition in order to help them improve their ability to function, reduce pain, and improve quality of life. One of these tools is radial pressure shockwave therapy (RPST). You might have heard of it… but what is it? And what is it supposed to do?
Simply put, RPST is a non-invasive therapeutic technique used primarily to treat musculoskeletal conditions, especially those that involve the tendons, ligaments, muscles, fascia, and general soft tissues, though can also be used on bones. It is used to stimulate healing in an injured area, but also reduces pain, inflammation, and improves range of motion and function.
It is a handheld device that creates mechanical ‘shockwaves’ that disperse their energy over a broad area but can reach depths of three inches within the body. This creates a microtrauma and mechanical stress at the tissues, such as tendons and fascia, which in turn then may affect a few biological processes, such as:
Improve pain: by stimulating sensory nerves near the tissues and releasing endorphins to help with acute and chronic pain
Improve circulation: improving circulation may affect metabolic activity locally, allowing for improved waste product removal and enhancing oxygen and nutrient delivery to the area
Improve collagen production: collagen production is increased due to the microtrauma caused by the shockwaves, which stimulates healing and strengthens the soft tissues
Improved healing: the mechanical stress and microtrauma caused by RPST results in improved collagen synthesis, angiogenesis (new blood vessel growth, which is helpful for healing), and improved tissue regeneration
Reduction in inflammation: RPST creates a reduction in local inflammatory markers in the area treated, often reducing inflammation and thus reducing pain associated with certain conditions, such as tendinopathies.
But how do shockwaves do this?
There’s quite a bit of technical science behind how shockwave therapy produces some of these results. Mechanotransduction plays a large role in shockwave therapy, which is the process by which the cells in the body convert mechanical stressors on tissues (ie: the shockwaves) into biochemical signals that trigger specific cellular responses. I won’t go into too much detail, but I will highlight some of the important points.
When the shockwaves reach the soft tissues they create fluctuations in pressure that result in shear stress, tensile stress, and microscale tissue deformation. This, in turn, activates mechanoreceptors on our cells, like fibroblasts which are important for collagen synthesis and tissue repair. A cascade of events then occur, including the expression of certain genes involved in the production of collagen type 1, and the release of various growth factors such as the vascular endothelial growth factor (VEGF). The release of certain growth factors may be responsible for neovascularization, or growth of new blood vessels, cell proliferation, and tissue remodeling. Additionally, the shockwaves mechanical stimulus on the tissues can impact a person’s perception of pain via the gate control theory. The idea is simple in that the non-painful mechanical stimulus on the tissues inhibit painful signals by activating Aβ fibers, which are large diameter nerve fibers. Painful stimuli is carried by small diameter nerve fibers, called c-fibers. Aβ fibers are activated, sending signals to the spinal cord and then to the brain. The spinal cord acts like a gate, allowing the signals from the large diameter nerve fibers through, and not the small diameter nerve fibers. Essentially, the signals from the shockwaves block the painful signals from reaching the spinal cord and the brain, thereby reducing pain.
Shockwave therapy has had a lot of great success in treating certain musculoskeletal conditions, even those that have not shown improvement with other therapeutic tools or techniques. Some of the many conditions it can treat are:
Tendinopathies (ie: achilles, tennis elbow, patellar tendon)
Plantar fasciitis
Rotator cuff injuries
Chronic pain conditions, such as fibromyalgia
Calcific tendinopathies (ie: rotator cuff or gluteal)
Myofascial trigger points
Non-specific Low back pain
Treatment is fairly simple and generally well tolerated. Ultrasound gel is placed over the area being treated and a handheld device is placed against the skin of the area. Inside the handheld device is a small metal piece. Once the machine is turned on this small metal piece is forcefully pushed against another metal piece in the end of the device against the person’s skin. This creates a clicking sound and ‘shockwave’ that is then dispersed through the ultrasound gel and into the person’s soft tissues. The machine will continue to create these shockwaves that sound like a continuous stream of clicking until the recommended number of shockwaves have been created.
Some redness, mild bruising, and mild local inflammation may occur due to treatment. Some discomfort can also be anticipated during treatment, especially in areas that are chronically inflamed or have calcifications. Typically, a person will report a reduction in pain levels immediately following treatment, though some mild soreness may occur for 1-2 days following as well.
There’s minimal down time following treatment. Most people will resume their normal daily activities immediately following treatment, though people are highly encouraged to avoid intense or vigorous activity for 24-48 hours following treatment to allow tissues to heal.
There are a few notable contraindications and precautions to using shockwave, therapy, however, including:
Pregnancy
Blood clotting disorders or the use of anticoagulants
Pacemakers
Active infection in the area being treated
Active cancer in the area being treated
Severe vascular conditions
The bottom line….
Shockwave therapy has actually been around for decades, so the technology isn’t new. But it is definitely gaining traction in the world of physical therapy for the treatment of various musculoskeletal conditions. The research available is promising and more research is coming out frequently. When used in conjunction with other physical therapy treatments it can be a very effective tool in relieving pain, improving function, and speed up the healing process.
