If you have ever had a tendon injury as a runner, you can relate that this type of injury can take weeks and even months to get better! For endurance athletes, the most common tendon injuries are in the lower body and can include high hamstring tendons, patellar tendons, Achilles’ tendons, foot tendons (peroneal tendons, posterior tibialis or anterior tibialis tendons) and even plantar fascia (because it behaves like a tendon!). These injuries do usually improve over time if treated with a combination of activity changes to reduce acute overload of the tendon (or fascia), strengthening exercises like eccentrics, building tendon load tolerance back up, and pain modulation techniques like massage or dry needling . However, as evidence-based physical therapists who work with a LOT of athletes with these types of injuries; we at Precision Performance are always looking for an extra ‘edge’ in treating these issues.
So, enter the possibility of using certain modality treatments, like shock wave therapy, for tendon injuries. The choice to use shock wave therapy is likely one that will be made with input from an orthopedic doctor or a physical therapist, both of whom could deliver the actual shock wave treatments. Furthermore, shockwave therapy may be reserved for individuals who are not getting better with the above treatments mentioned (i.e., “traditional physical therapy”). The possible benefits of using shock wave therapy are that it is safe, non-invasive, and could provide a method of reducing pain and improving function for tendinopathies that might not be responding to other treatments. In some cases, it has even been shown to reduce pain immediately after treatment or within one to two days, even for long standing, issues like tendinopathies (Dedes, 2018; Ikoma, 2018)
What is shock wave therapy and how does it work?
Shock wave therapy was first used for medical treatment in the 1980s as a non-invasive form of lithotripsy (i.e., to break up kidney stones or gallbladder stones). Since then, it has been used for musculoskeletal injuries to stimulate bone building cells (osteoblasts) to improve fracture healing and also has been used widely in many types of tendon injuries (e.g., Achilles’ tendinopathy, “Tennis elbow,” Plantar fasciitis/fasciopathy, rotator cuff tendinopathies, etc.). If used to treat tendons, it is thought that the way it helps with healing is to stimulate release of growth factors at the tendon-bone interface, stimulate cartilage remodeling cells (fibroblasts etc.) and to help with growth of new blood vessels in the area (i.e., neovascularization) though the research to date is not conclusive regarding these proposed mechanisms (Dedes, 2018).
There are different types of shockwave therapy in use for these injuries and some of these include (Robinson, 2020; Stania, 2019):
· Extracorporeal Shock Wave Therapy (ESWT): broad term used to describe the use of shock waves within orthopedic medicine. Common uses of ESWT include to promote fracture healing of bones or to treat tendon pain/injuries
· Focused Shock Wave Therapy: a type of ESWT, where the energy from the shockwaves is directed at a very specific area and this is higher in energy vs. radial shockwave therapy
· Radial Shock Wave Therapy (RSWT): low energy form of ESWT, where the shockwaves cover a broader area vs. focused shock wave therapy that is more targeted
The way it works is that a sound head applied to the skin delivers waves of energy that are small in duration (often 5-10 milliseconds), low frequency, and high amplitude. Shockwave therapy is delivered with a sound head that may remind you of therapeutic ultrasound. But, different than ultrasound, shockwaves are delivered as low frequency energy and so are not a heating modality like ultrasound. Shockwaves are delivered in a dose specified as number of ,“shocks” or “pulses,” (e.g., 1,000; 2,000 etc.) and treatments usually take less than 10-15 minutes to perform.
Is Shockwave Therapy Worth the ‘Hype'?
The short answer is that for some people with tendon pain, YES! In one study, people with different areas of tendinopathy (e.g., Achilles, Plantar fascia, Elbow, Rotator cuff) all had better improvements in pain and function when having 3-4 treatments of ESWT added to their conservative care (rest, physical therapy, NSAIDs medication) versus those who just got conservative treatments (Dedes, 2018). Additional studies have shown positive effects from using shockwave treatment to treat Achilles’ tendon pain (Rompe, 2009; Stania, 2019) and chronic plantar fasciitis (Sun, 2020).
Another study (Robinson, 2020), showed that radial shockwave treatments plus targeted intrinsic foot muscle strengthening improved pain and function in a series of 10 runners with posterior tibialis tendinopathy who “failed” (did not see enough improvements) conservative treatment (e.g., physical therapy care alone) and a case study on an adolescent runner with posterior tibialis calcific tendinitis improved with ESWT and was able to return to running after similarly failing conservative treatment (Ikoma, 2018).
(Figure Below from Robinson, 2020):
It is important to mention that in the majority of these studies (and in clinical practice), ESWT is not used as a stand-alone treatment but is added to physical therapy plans including exercise and manual therapy. Strengthening lower leg muscles, like the gastrocnemius and soleus in the calf and foot intrinsic muscles in addition to working on motor control and stability is a crucial part of rehabilitation for most runners. It is also a needed factor in preventing injuries like this from coming back. If you are struggling with a tendon injury, it could be helpful to get some guidance from a physical therapist or another medical provider on the best treatment options for you, which may include recommending shock wave treatment!
Dedes V, Stergioulas A, Kipreos G, Dede AM, Mitseas A, Panoutsopoulos GI. Effectiveness and Safety of Shockwave Therapy in Tendinopathies. Mater Sociomed. 2018 Jun;30(2):131-146.
Ikoma K, Hara Y, Maki M, Ohashi S, Ueshima K, Kubo T. Extracorporeal Shock Wave Therapy for an Adolescent Patient with Calcific Tendinopathy of Posterior Tibial Tendon: A Case Report. PRM. 2018;3(0):n/a.
Robinson D, Mitchkash M, Wasserman L, Tenforde AS. Nonsurgical Approach in Management of Tibialis Posterior Tendinopathy With Combined Radial Shockwave and Foot Core Exercises: A Case Series. The Journal of Foot and Ankle Surgery. 2020;59(5):1058-1061.
Rompe JD, Furia J, Maffulli N. Eccentric Loading versus Eccentric Loading plus Shock-Wave Treatment for Midportion Achilles Tendinopathy: A Randomized Controlled Trial. Am J Sports Med. 2009;37(3):463-470.
Stania M, Juras G, Chmielewska D, Polak A, Kucio C, Król P. Extracorporeal Shock Wave Therapy for Achilles Tendinopathy. BioMed Research International. 2019;2019:1-13.
Sun K, Zhou H, Jiang W. Extracorporeal shock wave therapy versus other therapeutic methods for chronic plantar fasciitis. Foot and Ankle Surgery. 2020;26(1):33-38.