Sex-Based Differences in Biomechanical Function for Chronic Low Back Pain and how it Relates to Pain Experience

Abstract This study examined sex-based differences in biomechanical function and pain experience of individuals with chronic low back pain (LBP). The significant variability in biomechanical function among patients with chronic LBP underscores the importance of developing a novel mathematical method to quantify full body movement, rather than relying on individual parameters from biomechanical analyses. This method was used to examine a patient-specific factor, biological sex, that may inform motion heterogeneity among LBP patients. The results highlighted significant biomechanical sex-based differences in patients with LBP during the sit-to-stand dynamic transition, which was largely driven by variations in trunk movement. Males showed increased biomechanical impairment compared to females, although there was no sex-based difference in total time. Further, measuring pressure pain threshold highlighted lower pain sensitivity in males compared to females. There was a weak but significant negative association between pressure pain thresholds and biomechanical function for males, while females lacked an association. Possible explanations include reduced interoceptive awareness or increased kinesiophobia in males, which may influence movement patterns. This research is an initial step in uncovering the complex relationship between patient-specific factors influencing LBP disability, laying the groundwork for further exploration, and paving the way for improving outcomes with patient-specific treatments.