Evaluating the Prevalence of Lumbar Myofascial Pain Syndrome in Patients with Non-specific Chronic Low Back Pain and a Normal MRI Study

Abstract Introduction: Low back pain is a very common disorder that affects a significant percentage of people in the community (1). As a non-mechanical cause, myofascial pain is a primary disorder which may produce lumbar and lower limb pain and is not necessarily secondary to other diagnosis (2-5). Trigger points are the main symptoms of myofascial pain which may mimic the radicular pain in spinal disorders (6, 7). Objective: To evaluate the prevalence of lumbar myofascial pain syndrome in patients with non-specific chronic low back pain and a normal MRI study. Materials and Methods: This cross-sectional study was conducted on 171 patients with chronic low back pain and normal MRI report (age:43.96 ±13.6years), (weight:76.7± 71.74 kg), ( height: 166.44 ± 7.15 cm). Incidence of this syndrome was evaluated in 16 lumbar and lower extremity muscles (8). The trigger points finding was performed by tissue palpation (9). Results: Females constituted 71.7 % and males 28.3 % of the participants. The patients maximum incidence percentages were in quadratus lumborum (47.7℅)‚ multifidus(43℅)‚ gluteus medius (36℅)‚ gluteus maximus (34.9℅)‚ piriformis (32.4℅) and other muscles involvement was below 30℅. In 27.7% of the patients only two muscles were involved. A significant correlation was shown between the number of involved muscles and age(r=0.21, p=0.005) and pain and disability(r=0.46, p=0.03). Conclusion: Myofascial pain syndrome should be considered as a hallmark in differentiating chronic low back pain regardless of MRI finding. Conflict of interest: non declared