Activation of transversus abdominis and fear avoidance beliefs have both been linked to low back pain (LBP). In this exploratory study, the authors goal was to investigate associations between fear avoidance beliefs at baseline and deep abdominal muscle activation after an 8-week period of supervised exercises for chronic LBP. They studied a cohort of patients with chronic non-specific LBP (N = 108) enrolled in a clinical trial longitudinally. Measurements of fear avoidance beliefs for physical activity and work were taken prior to intervention. Activation in transversus abdominis and obliquus internus abdominis during abdominal drawing-in manoeuvre and rapid arm flexion was measured by ultrasound prior to and following intervention. Associations between baseline fear avoidance beliefs and deep abdominal muscle activation after exercises were analysed with multiple linear regression methods. They found that high fear avoidance beliefs for physical activity (≥16 on the subscale) were negatively associated with transversus abdominis slide after the intervention period, β = −4.92 (−8.40 to −1.45). No associations between fear avoidance beliefs for physical activity and abdominal muscle onset, transversus abdominis or obliquus internus contraction ratio were found. None of the muscle activation parameters were associated with fear avoidance beliefs for work.
Their study indicates that there is some negative association between fear avoidance beliefs for physical activity prior to intervention and transversus abdominis recruitment measured by lateral slide following intervention. They did not find any other significant associations between fear avoidance beliefs and abdominal muscle activation. They were not able to exclude random findings, meaning that their results should be considered hypothesis generating for further investigations.