Extra-corporeal Shock Wave Therapy effective for pain relieve
Mechanical waves applied to outside of the body have been used since the 1980s in urology to destroy kidney stones. As this technique was then used to treat urinary lithiasis, these therapeutic shock waves were called “lithotripsy” or “extracorporeal shock wave therapy” or “ESWT” (for Extra-corporeal Shock Wave Therapy).
In the early 1990s, they began to be studied for their ability to promote healing of fractures, particularly in cases of delayed consolidation or pseud arthrosis. Subsequently, this therapy has been increasingly used to treat different types of musculoskeletal lesions, such as shoulder calcifications, tendinopathies (especially enthesopathies), bursitis and plantar fasciitis. New applications are regularly suggested such as osteochondritis dissection, osteonecrosis, partial tear of the cuff, etc. They differ from ultrasound which are continuous high-intensity ultrasonic waves generating heat in the body (effect used), whereas in shock waves the rise in temperature is negligible.
A shock wave generating system includes an electrical energy source, an electro-acoustic conversion mechanism and a shock wave focusing apparatus. There are three systems of apparatus producing shock waves: Electro-hydraulic (HMT, MTS, Orthospec); Piezoelectric (Wolf); Electromagnetic field (Dornier Epos, Siemens). Radial shock wave emitting systems must be classified separately. Indeed, the emitted waves are of mechanical and non-acoustic origin, their radial and non-focal diffusion, and are devoid of negative phase (RSWT). Nevertheless, in addition to their attractive price, the latter showed some efficacy in the treatment of tendinopathies (43 to 73% good results depending on the location after 6 weeks, according to an open study. More details about shockwave therapy can be found at https://nydnrehab.com/treatment-methods/shockwave/.
For the effects of shock waves in this area, the following assumptions have been made: Stimulation of the growth of osteoblasts, neo-vascularization in bone and enthesis, biofeedback, release of endorphins, structural change in tissues and stimulation of regeneration, structural change in the calcium deposit followed by Its reabsorption by the body; Some authors believe, for example, that in the case of degenerative or chronic tendinopathies, the stimulation of an inflammatory process, for example by an incision during surgery, with the Augmented Soft Tissue Mobilization (ASTM) or ESWT generators or RSWT, could help stimulate the regeneration of the tendon. This may also explain some suggested effects of Cyriax friction, MTP, or eccentric exercises.
Extracorporeal shock wave therapy does not appear to be effective in relieving pain or disability associated with tennis elbow or epicondylitis according to some studies. Epicondylitis, inflammation of the tendons which enter the external part of the elbow can sometimes occur as a result of violent trauma, but most often occur after frequent trauma, overwork in the elbow area or The intense repetition of certain movements. These excessive stresses of the muscles of the forearm are observed in particular in the context of sports (tennis, in the reverse lifts, golf, or more rarely rowing and weightlifting) but also sometimes in the professional activity , Especially among those working in the construction sector.
It is believed that their beneficial effect results from the fact that they cause microscopic lesions stimulating the healing of the affected tissue. However, the quality of data available on the effectiveness of this strategy in the management of epicondylitis remains less.