Chronic non-specific low back pain (CNLBP) has become a major public health problem that needs to be addressed. Thus, our study aimed to compare the activation of contingent negative variation (CNV) and anticipatory postural adjustments (APAs) in patients with CNLBP with those in healthy subjects, and to correlate them with clinical symptoms.

This study included 21 patients with CNLBP and 20 healthy controls. Demographic data and assessment of APAs were collected for both groups. Low back pain-related scales were additionally collected from the CNLBP group. The activation time and intensity of core muscle group of APAs were recorded during the anticipatory postural conditioning task (rapid arm lift) using sEMG, and the CNV amplitude at the Cz point during the exercise preparation period was captured using EEG. Two-factor repeated measures ANOVA and Pearson's correlation analysis were used to compare between-group differences and central-peripheral index associations.

During the APAs task, the CNLBP group showed delayed activation of the left transversus abdominis (p<0.001) and left erector spinae (p<0.05) APAs, reduced activation intensity of the right erector spinae (p = 0.02) and left multifidus (p = 0.03), and a significant reduction in the CNV amplitude compared to the healthy group (p = 0.01). Correlation analysis showed that CNV wave amplitude was negatively correlated with the time of APAs in the left transversus abdominis muscle (r = -0.58, p = 0.02), VAS score (r = - 0.53, p = 0.04), and FABQ score (r = - 0.67, p = 0.01).

This study linked reduced CNV amplitude to delayed APA activation in CNLBP patients, indicating insufficient central motor readiness as a neural mechanism for impaired anticipatory postural control.