Figure 6.

Semi-logarithmic relationships between pain thresholds and MEAP. FM subjects (black triangles) had pain thresholds below 2.3 kg/cm² (heavy, black error bars). Normal subjects (grey circles, cabled grey error bars) had lower MEAP and higher pain thresholds compared to FM. LBP subjects (open diamonds) had results that covered the full ranges for both variables (upper right error bars). The data for all subjects were linearly correlated (Pearson's correlation coefficient R = -0.38, p < 0.05) with an explained variance (R²) of 0.15. The line appears curved on this semi-logarithmic plot.