What is shockwave and can it help with lower limb injuries?
Shockwave is not a new treatment modality; it has been around since the 1980s where it was initially used to treat kidney stones. Its use in lower limb injuries, is more recent (since the 1990s) where there are several conditions where it has been used effectively and, in some instances, is a legitimate alternative to injections and even surgery.1 A shockwave is a form of an acoustic wave that carries energy and can propagate through tissues causing a biological response.
When referring to this treatment modality, shockwave is more of an abbreviation with the correct term being extracorporeal shockwave therapy. There are a few different types of shockwave therapy that can be used to treat musculoskeletal conditions. The most common for lower limb injuries is extracorporeal radial shockwave therapy; less common is extracorporeal focused shockwave therapy.
The most common musculoskeletal conditions for which shockwave therapy is used are lower limb injuries, particularly plantar fasciitis and Achilles tendinopathy. These conditions are typically treated once per week and the average treatment length is about five sessions but can vary between two and eight sessions. When performed correctly, for the right person and in conjunction with good advice and appropriate exercise or load modification, shockwave therapy has a success rate as high as 90%2 - this is without the need for injections, surgery and consequently no down time.3,4
Other conditions that may be treated with radial shockwave therapy include tendon tenosynovitis, tibialis posterior tendinopathy, muscular trigger points, patella and quadriceps tendinopathy osteoarthritis of the knee/s, gluteal medius tendinopathy or greater trochanter pain syndrome (which includes hip bursitis as part of that syndrome) and medial tibial stress syndrome (shin splints).
How shockwave works
Different mechanisms of action of radial shockwave have been proposed over the years. The production of cavitation bubbles within the tissue is one of the physical mechanisms that has been shown to occur in the tissue5 and may be in impetus to a number of biological processes in the tissue. In terms of the biological process, there have been multiple mechanisms identified including down-regulation of substance P released by C nerve fibres6 which assists with the down regulation of pain.
This reduction in substance P would also reduce neurogenic inflammation7 which again will assist with pain relief. Apart from pain relief, shockwave can also induce protein biosynthesis, cell proliferation, neuro and chondroprotection, and destruction of calcium deposits in musculoskeletal structures.8 More recently, shockwave has been shown to increase lubricin expression/production.9 Increased lubricin expression may contribute to pain and symptom relief in musculoskeletal disorders by decreasing erosive wear on tendons and septa.
Muscle injuries
Muscle injuries in sports do result in player lay-off times and can have an impact on individual and team performance. Extracorporeal shockwave therapy has been used in premier league soccer for a number of years, but the data to date has not been shared outside the clubs. Morgan10 compared injury data by Ekstrand11 and showed that the use of shockwave significantly reduced the mean lay-off times in professional soccer players (reduced by 58% for type 1a injuries, 55% for 2b injuries, and by 21% for 3a injuries).
The results suggest that use of shockwave therapy in acute muscular injuries has significant benefits with respect to healing times and returning back to pre-injury status.
New emerging areas in shockwave therapy
There are other emerging areas of shockwave therapy in musculoskeletal therapy. These include treatment of spasticity via induction of transient dysfunction of the nerve condition at the neuromuscular junction12 (similar action to Botox) so watch this space!
Overall, radial shockwave therapy is a proven safe technology and treatment modalities, with very little side effects and no down time (compared with surgery). Shockwave therapy has substantial scientific evidence substantiating its use with these musculoskeletal conditions. If you are unsure if shockwave therapy is right for you, please discuss this with a health professional in a clinic that specialised in the modality. They will be the most equipped to navigating you in deciding if it is the right modality for your condition.
Gavin Corica
Physiotherapist, Exercise Physiologist, Internationally accredited shockwave therapist, SCDA trainer
B.Sc(Nutrition & Food Science), Grad.Dip.Sci(Exercise Rehabilitation), B.Sc(Physiotherapy)
References
1 Wuerfel T, Schmitz C, Jokinen LLJ. The Effects of the Exposure of Musculoskeletal Tissue to Extracorporeal Shock Waves. Biomedicines. 2022, 10(5):1084.
2 Wang CJ, Ko JY, Chan YS, Weng LH, Hsu SL. Extracorporeal shockwave for chronic patellar tendinopathy. Am J Sports Med. 2007, 35(6):972-8.
3 Li H, Lv H, Lin T. Comparison of efficacy of eight treatments for plantar fasciitis: A network meta-analysis. J Cell Physiol. 2018, 234(1):860-870.
4 Othman AM, Ragab EM. Endoscopic plantar fasciotomy versus extracorporeal shock wave therapy for treatment of chronic plantar fasciitis. Arch Orthop Trauma Surg. 2010, 130(11):1343-7.
5 Csaszar, Nikolaus & Angstman, Nicholas & Milz, Stefan & Sprecher, Christoph & Kobel, Philippe & Farhat, Mohamed & Furia, John & Schmitz, Christoph. (2015). Radial Shock Wave Devices Generate Cavitation. PloS one. 10.
6 Andersson G, Backman LJ, Scott A, Lorentzon R, Forsgren S, Danielson P. Substance P accelerates hypercellularity and angiogenesis in tendon tissue and enhances paratendinitis in response to Achilles tendon overuse in a tendinopathy model. Br J Sports Med. 2011, 45(13):1017-22.
7 Richardson JD, Vasko MR. Cellular mechanisms of neurogenic inflammation. J Pharmacol Exp Ther. 2002, 302(3):839-45.
8 Simplicio CL, Purita J, Murrell W, Santos GS, Dos Santos RG, Lana JFSD. Extracorporeal shock wave therapy mechanisms in musculoskeletal regenerative medicine. J Clin Orthop Trauma. 2020, 11(Suppl 3):S309-S318.
9 Zhang, D., Kearney, C. J., Cheriyan, T., Schmid, T. M., & Spector, M. Extracorporeal shockwave-induced expression of lubricin in tendons and septa. Cell and Tissue Research. 2011, 346(2), 255
10 Morgan, J.P.M., Hamm, M., Schmitz, C. et al. Return to play after treating acute muscle injuries in elite football players with radial extracorporeal shock wave therapy. J Orthop Surg Res, 2021, 16, 708.
11 Ekstrand J, Hägglund M, Waldén M. Epidemiology of muscle injuries in professional football (soccer). Am J Sports Med. 2011, 39(6):1226–32.
12 Vidal X, Martí-Fàbregas J, Canet O, Roqué M, Morral A, Tur M, Schmitz C, Sitjà-Rabert M. Efficacy of radial extracorporeal shock wave therapy compared with botulinum toxin type A injection in treatment of lower extremity spasticity in subjects with cerebral palsy: A randomized, controlled, cross-over study. J Rehabil Med. 2020, 30;52(6):jrm00076.