The immediate effect of simulating leg-length discrepancy on spinal posture and pelvic position: a cross-over designed study.

Leg-length discrepancy (LLD) is a common condition that may cause posture changes and clinical consequences. Rasterstereography is a valid and reliable method that analyzes posture without radiation exposure and invasive procedures. This study aimed to assess the immediate effect of artificial LLD on pelvic position and spinal posture in athletes. Twenty-four elite karate athletes (14 men, 10 women) were included in the study. Sagittal imbalance, coronal imbalance, pelvic obliquity, pelvic torsion angle, thoracic kyphosis angle and lumbar lordosis angle were measured at different artificial LLD heights (5 -10 -15 -20 mm). Statistical analysis was performed with One-Way ANOVA with repeated measures or Friedman test. In cases where there were significant differences, pairwise comparisons were performed with least significant differences (LSD) test or Wilcoxon signed rank test. There were statistically significant differences in pelvic obliquity (p = 0.001), pelvic torsion (p = 0.001) and lumbar lordosis (p = 0.001) with varying LLD. However, there was no significant difference in sagittal imbalance, coronal imbalance and thoracic kyphosis angle. It has been observed that even a 5-mm LLD causes pelvic position and spinal posture changes. Future studies detecting these changes in populations with LLD via rastersterography may prevent possible musculoskeletal disorders.