The pain pathomechanism of chronic low back pain (LBP) is complex and the available diagnostic methods are insufficient. Patients present morphological changes in volume and cross-sectional area (CSA) of lumbosacral region. The main objective of this study was to assess if CSA measurements of pelvic muscle will indicate muscle atrophy between asymptomatic and symptomatic sides in chronic LBP patients, as well as between right and left sides in healthy volunteers. In addition, inter-rater reliability for CSA measurements was examined. The study involved 71 chronic LBP patients and 29 healthy volunteers. The CSA of gluteus maximus, medius, minimus and piriformis were measured using the MRI manual segmentation method. Muscle atrophy was confirmed in gluteus maximus, gluteus minimus and piriformis muscle for over 50% of chronic LBP patients (p < 0.05). Gluteus medius showed atrophy in patients with left side pain occurrence (p < 0.001). Muscle atrophy occurred on the symptomatic side for all inspected muscles, except gluteus maximus in rater one assessment. The reliability of CSA measurements between raters calculated using CCC and ICC presented great inter-rater reproducibility for each muscle both in patients and healthy volunteers (p < 0.95). Therefore, there is the possibility of using CSA assessment in the diagnosis of patients with symptoms of chronic LBP.

Purpose: Recent redefinitions of pain emphasize the importance of the previously overlooked recurrent low back pain (LBP). Understanding the direct medical cost for recurrent LBP cases based on the cost per visit is crucial economically. We aimed to compare the cost per visit for LBP and recurrent LBP, including the impact of gender and type of medical service, estimating the approximate annual cost of recurrent LBP. Patients and Methods: Data on LBP categorized according to ICD-10 codes (G54, G55, M45, M46, M47, M48, M49, M51, M53, and M54) from the Polish National Health Fund (NHF) and Opolskie Rehabilitation Center (OCR) were analyzed based on the recurrent state as outlined in the new chronic pain definition. Results: In OCR, a recurrent LBP was confirmed for 22.78% of patients, of which 59.72% were female (p< 0.001). The mean value of a single procedure for recurrent LBP was 110.56 EUR, it was significantly higher for males (135.35 EUR) than for females (92.94 EUR) (p=0.008). Recurrent LBP generated a higher cost per visit for medical services than LBP (p< 0.001), except for physiotherapy. Notably, males had a higher cost per visit in inpatient admissions, while females had a significantly higher cost per visit in physiotherapy services for both LBP and recurrent LBP. Moreover, recurrent LBP generated a statistically higher cost per visit for medical services than non-recurrent cases, except for physiotherapy. The average annual cost of LBP-related medical services in Poland was € 243,861,639. Conclusion: Recurrent LBP accounts for 5% of total direct LBP costs and has a higher cost per visit than LBP, excluding physiotherapy services. Gender significantly affected per-visit costs, with males having more inpatient admissions and females utilizing more physiotherapy services for both LBP and recurrent LBP.

Background: Gluteus minimus myofascial trigger points (TrPs) can reproduce lower-limb referred pain and may be accompanied by autonomic phenomena and motor responses. Thermographic assessment during TrP stimulation may identify vasomotor changes in the referred pain region, while surface electromyography (sEMG) can capture short-term changes in motor activation following provocation.Aim of the study: This four-case series aimed to describe divergent thermographic and short-term sEMG response patterns following provocation of referred pain from gluteus minimus TrPs in individuals with chronic spine-related leg pain.Case report: Four patients underwent standardized gluteus minimus TrP provocation with thermographic assessment conducted at baseline, at the end of stimulation, and at final observation, along with pre- and post-stimulation knee-extension sEMG. All patients reported reproduction of lower limb referred pain. Thermographic analysis revealed heterogeneous autonomic profiles, with vasoconstrictive responses observed in Cases 1 and 3 and vasodilatory responses in Cases 2 and 4. The sEMG profiles were also heterogeneous: Case 1 demonstrated increased motor activation, Cases 2 and 3 exhibited reduced and delayed activation, and Case 4 displayed a relatively stable peak EMG response with slower activation dynamics.Conclusions: Provocation of gluteus minimus TrPs may elicit divergent autonomic and motor responses rather than a uniform physiological pattern. Combined thermographic and sEMG assessment may help characterize distinct phenotypes of referred pain response. However, these observations should be interpreted as exploratory given the case-series design and movement-related limitations of thermographic region-of-interest analysis.