The difference in multifidus muscle morphology and motor control in non‐specific low back pain with clinical lumbar instability and healthy subjects: A case‐control study

Abstract

BackgroundLow back pain (LBP) with clinical lumbar instability (CLI) is considered a subgroup of back pain. Poor core stability function and/or lack of motor controls are thought to play a role in inappropriate inter‐segmental movements and pain. There is no study investigating the changes in the lumbar multifidus muscle (LMM) morphology and motor control in this subgroup of patients.ObjectiveTo assess motor control components and morphological changes of LMM in the patients suffering from chronic nonspecific low back pain (CNSLBP) with CLI.DesignObservational case‐control study.MethodsThirty‐two patients suffering from (CNSLBP) with CLI and 32 healthy individuals were included. The muscle force element of lumbar motor control was assessed by using (the active straight‐leg raise test, leg lowering test, and Trendelenburg test). Ultrasonography was used to assess changes in the LMM morphology.ResultsThere was a significant decrease in motor control (p = 0.0001), an increase in LMM fatty infiltration (p = 0.002), and a decrease in the thickness of LMM in patients suffering from CNSLBP during contraction (p = 0.006), during rest (p = 0.018). The cross‐section area of the LMM showed no statistically significant differences during rest on the right and left sides (p = 0.827, 0.220 respectively) and contraction (p = 0.160, 0.278 respectively) between patients and healthy subjects.ConclusionMotor control and the morphology of LMM in patients with CNSLBP with CLI may provide insight into the mechanisms of underlying pain and their effect on muscle function and structure.

Comparison of lumbar muscle morphology in patients with chronic nonspecific low back pain with and without clinical lumbar segmental instability

“…Several studies have investigated the relationship between lumbar muscle morphology and different types of LBP. Consistent with the results of the present study, the changes in motor control, increasing MF fat infiltration and decreasing MF thickness were reported by Abdelaty et al in patients with CNLBP with clinical lumbar instability [ 25 ]. Others such as Dayani et al [ 26 ] found smaller MF size in CNLBP patients and Gobert et al [ 27 ] found increased fat infiltration in the MF muscle with no change in total CSA in patients with CNLBP compared to patients with acute LBP.…”