Cognitive Behavioral Therapy With Stabilization Exercises Affects Transverse Abdominis Muscle Thickness in Patients With Chronic Low Back Pain: A Double-Blinded Randomized Trial Study

OBJECTIVE: Nonspecific chronic low back pain (NCLBP) is a major public health and global socioeconomic burden with a variety of symptoms, such as fear-avoidance behaviors. This study aimed to evaluate the effect of cognitive behavioral therapy (CBT) associated with stabilization exercise (SE) on thickness of transverse abdominis (TrA) muscle in patients with NCLBP. METHODS: Forty patients with NCLBP were randomly assigned into experimental CBT associated with SE (n = 20) and control groups without SE (n = 20). Transverse abdominis muscle thickness was assessed during abdominal drawing in maneuver (ADIM) and active straight leg raise (ASLR) of the right lower limb using ultrasound imaging. Fear-avoidance belief and disability were evaluated using a fear-avoidance belief questionnaire (FABQ) and a Roland-Morris disability questionnaire (RMDQ) before and after intervention. RESULTS: Mixed-model analysis of variance indicated that the effect of time was significant for the right and left TrA contraction thickness during ADIM and left TrA contraction thickness during ASLR (P < .05). However, the experimental group exhibited higher right and left TrA muscle thickness compared with the control group during ADIM (P = .001). Moreover, there were no significant differences between groups in the thickness of TrA muscle during ASLR (P > .05). The effect of time was significant for FABQ (P = .02) and RMDQ (P = .01); however, the effect of group was significant for the FABQ after intervention (P = .04). CONCLUSIONS: Stabilization exercise associated with CBT is more effective than SE alone in improving fear avoidance belief and in increasing the thickness of the TrA muscle during ADIM task.