Molecular Mechanisms Underlying the Pain-Relieving Effects of Extracorporeal Shock Wave Therapy: A Focus on Fascia Nociceptors

Abstract

In recent years, extracorporeal shock wave therapy (ESWT) has received increasing attention for its potential beneficial effects on various bone and soft-tissue pathologies, yielding promising outcomes for pain relief and functional recovery. In fact, ESWT has emerged as an alternative, non-invasive, and safe treatment for the management of numerous musculoskeletal disorders, including myofascial pain syndrome (MPS). In particular, MPS is a common chronic painful condition, accounting for the largest proportion of patients affected by musculoskeletal problems. Remarkably, sensory innervation and nociceptors of the fascial system are emerging to play a pivotal role as pain generators in MPS. At the same time, increasing evidence demonstrates that application of ESWT results in selective loss of sensory unmyelinated nerve fibers, thereby inducing long-lasting analgesia. The findings discussed in the present review are supposed to add novel viewpoints that may further enrich our knowledge on the complex interactions occurring between disorders of the deep fascia including changes in innervation, sensitization of fascial nociceptors, the pathophysiology of chronic musculoskeletal pain of MPS, and EWST-induced analgesia. Moreover, gaining mechanistic insights into the molecular mechanisms of pain-alleviating effects of ESWT may broaden the fields of shock waves clinical practice far beyond the musculoskeletal system or its original application for lithotripsy.

Effect of Shockwave Therapy on Postmenopausal Sacroiliac Joint Pain: A Randomized Controlled Trial

“…Both positive and negative pressure impulses provoke physical/mechanical consequences like absorption, reflection, refraction, and cavitation in the underlying treated tissues that are followed by numerous molecular and biological consequences, because of mechano-transduction. Indeed, shockwaves can activate various cell signaling pathways and induce the production of a variety of biomolecules [26] .…”

“…In the current study, the advantageous effect of shockwave therapy on reducing pain sensitivity and intensity along with recovering functional disability could be attributed to several mechanisms of action. shockwave therapy can relieve pain in musculoskeletal tissues via selectively destroying unmyelinated fibers, reducing neuropeptides related to pain, hyperstimulating nociceptors, modulating neurotransmission of pain, and reducing the levels of mediators of inflammation such as interleukins and matrixins [26,27] . Moreover, the shock waves produce micro-destruction, which causes micro-tearing of tissues with minimal or insufficient vascularization to promote revascularization via local growth factors production and stem cells mobilization, resulting in blood flow increase to these tissues and a subsequent reduction in muscular tension and tissue adhesions [28,29] .…”

“Sport and Anatomy”: Teaching, Research, and Assistance at the University of Pisa

“…As demonstrated by several recent research articles [20][21][22][23][24][25][26][27][28][29], all these research activities led to many publications in the last four years in different peer-reviewed international journals, with a total Impact Factor of 22.4, and a total number of citations of 141 (35.25 mean citation per year) (source: Scopus.com; last update: 21 June 2022).…”

Immediate Effects of Extracorporeal Shock Wave Therapy in Fascial Fibroblasts: An In Vitro Study

“…Furthermore, different hypotheses have been proposed on the molecular mechanisms by which ESW treatment alleviates the pain in the musculoskeletal system [ 30 ], but so far, only the nerve component without the connective component has been considered [ 30 ]. However, Pavan et al [ 31 ], in considering the complex structure of deep fascia, reported that in myofascial pain, deep fascia could be subjected to two different kinds of alteration: (1) damage of loose component (rich in water and HA), affecting the sliding system between different layers and (2) damage of fibrous component, affecting the capacity of force transmission.…”