REFERRED MUSCLE PAIN, SOME CONSIDERATIONS OF ITS SIGNIFICANCE IN PRACTICE
Authors: Мratskova Galina , Cvetanov Todor , Dimitrov Sider 
Published: March 2024

Muscle pain is a common symptom in many musculoskeletal disorders. When it is local as a result of a muscle injury, correct diagnosis does not appear difficult. Referred muscle pain is a symptom associated with diagnostic and therapeutic challenges. It can be a consequence of an injury that develops elsewhere in the body: a skeletal muscle in another area or joint, or it can often be associated with a visceral injury (in this case we have referred muscle pain or secondary muscle pain). The aim of this article is to make a review of the available literature studying the nature, diagnosis, and treatment of referred pain and its relevance to clinical practice. Materials and Methods: In this review, the available scientific articles concerning the field of reflected pain are reviewed: Google Scholar, Pubmed, Science Direct Web of Science, Scopus, and scientific articles in Cyrillic) databases were reviewed. The search results included keywords that define the current problem: muscle pain, referred muscle pain, nociceptive pain, neuropathic pain, radicular pain, somatic, viscera, visceral pain, hyperalgesia, central sensitization, spinal sensitization, visceral hyperalgesia; viscerosomatic convergence; descending modulation, muscle contraction, muscle hypotrophy. Results: When searching for topical scientific results, not many publications have been found. Some of them were older, in some possible mechanisms of pathogenetic manifestation of referred muscle pain were discussed. One article suggested the existence of another possible mechanism besides the generally described ones. Several hypotheses concerning the occurrence of this secondary pain were found to exist, without giving priority to any theory. Most articles described different localizations of symptoms of referred pain and their relationship to other body structures (muscle or joint in a distant region) or internal organ dysfunction or disease. Most of the authors emphasized on the need of better knowledge of this type of pain and the distinction between local, nociceptive, radicular, and neuropathic pain that has a precise clinical characteristic and evidence of a specific injury to an underlying body structure. Conclusion: Knowledge and diagnosing of referred muscle pain is important for clinical practice. Differentiation from primary skeletal muscle pain is still a challenge, but a good knowledge of the problem can provide solutions, although the pathogenetic mechanisms of its occurrence remain unclear. It is likely that the totality of central-nervous mechanisms, the convergence of information from different somatic areas in the dorsal horn and/or its facilitation in it as well as at the level of the thalamus, and the phenomenon of hyperexcitability are essential, although the notion that referred muscle pain has a peripheral origin should not be ignored. Knowledge and targeted search for referred secondary pain could prevent some diagnostic problems and at the same time treat it with appropriate treatments, including the means of physiotherapy.