Comparison of the Cross-Sectional Area and Fat Infiltration of Paraspinal Muscles in Patients with Chronic and Acute Low Back Pain

This study aimed to evaluate the cross-sectional area (CSA) and fat infiltration of paraspinal muscles in the level of L5 in patients with chronic and acute low back pain (LBP).
This pilot study was done on 30 patients with acute and 30 with chronic low back pain. Body mass index (BMI), pain score (using visual analog scale), patients’ disability (using Oswestry Disability Index), duration of pain, cross-sectional area of paraspinal muscles, and fat infiltration in multifidus, erector spinae, and psoas muscles (using magnetic resonance imaging) were measured and compared in the two groups of patients.
Findings: Patients body mass index and pain score were not significantly different between studied groups (P > 0.050 for both). Patients’ disability index score was significantly higher in acute low back pain group than chronic group (P = 0.007). The mean cross-sectional area in multifidus, erector spinae, and psoas muscles was not significantly different between the groups (P > 0.050 for both). The mean muscles fat infiltration was significantly higher in chronic low back pain than the acute grroup (P The higher rate of fat infiltration of paraspinal muscles in patients with chronic low back pain compared to those with acute pain may show its potential role in chronic low back pain.