The condition of the erector spinae muscle in patients with chronic nonspecific low back pain

Abstract

Myofascial pain syndrome caused by damage to the paravertebral muscles is considered as one of the causes of chronic back pain. At the same time, there is not enough information about the condition of the paravertebral muscles, and it is contradictory.The aim of the work is to elucidate the presence and severity of structural and functional changes in the paravertebral muscles and their role in the development of chronic nonspecific pain in the lower back in women.Material and methods. Morphological, immunohistochemical examination of a muscle tissue biopsy was performed in 17 patients aged 24 to 59 years (average age — 41.5 ± 12.1 years) with CNS (average duration of pain syndrome 10.0 ± 6.9 months) caused by myofascial pain syndrome, as well as determination by gel electrophoresis of the isoform composition of giant sarcomeric proteins titin and nebulin.Results. Morphological examination revealed no signs of necrosis, proliferation of connective and adipose tissue, inflammatory infiltration. The transformation of the myosin phenotype in the direction of an increase in the proportion of “fast” type II muscle fibers was revealed in the biopsies of the patients’ muscles. A decrease in the content of giant titin and nebulin proteins associated with myosin and actin in the sarcomere was also found.Conclusion. The data obtained indicate a violation of the contractile function of the paravertebral muscle in CNS.