Figures plot standardized effect size differences between control and chronic lower back pain groups when comparing a) left internal obliques to left external obliques, b) right internal obliques to right external obliques, c) left internal obliques to left rectus abdominus, and d) right internal obliques to right rectus abdominus. Each graph represents a muscle group with plots representing the magnitude of difference between ratios between muscle groups between the two groups in the different postures. Positive values indicate the chronic lower back pain group had higher normalized values. Error bars indicate 95% confidence limits of the mean difference between groups. The shaded area of the graph indicates the region in which the difference between groups is trivial (i.e. between -0.20 and 0.20 standardized effect sizes). Asterisks (*) indicate conditions with >75% likelihood that the difference exceeds the smallest worthwhile difference.