Comparison of the Immediate Effects of Sitting Hip Flexion and Backward Rocking Exercise on Hip Flexion Tension and Pelvic Posterior Tilt Angle in Individuals with Excessive Posterior Pelvic Tilt

Purpose: This study compared the effects of sitting hip flexion (SHF) and backward rocking exercise (BRE) on hip flexion tension and pelvic posterior tilt angle in individuals with excessive posterior pelvic tilt.The purpose was to examine how two exercises with different neuromuscular control strategies influence the hip flexor output and pelvic alignment during hip flexion.Methods: Eighteen university students with posterior pelvic tilt were assigned randomly to the SHF (n= 9) or BRE group (n= 9).Hip flexion tension was measured using the Smart KEMA tension sensor, and the pelvic posterior tilt angle was assessed using the 4DMT-IMU inclinometer during a standing hip flexion task.The measurements were obtained before and after a single 30-minute exercise session.A 2 2 mixed-design repeated measures ANOVA was performed to analyze the effects of time and group, and post-hoc paired t-tests with a Bonferroni correction were conducted for the within-group comparisons.Results: SHF and BRE increased the hip flexion tension significantly and decreased the pelvic posterior tilt angle significantly after the intervention (p< 0.025).A significant time group interaction was observed for hip flexion tension, indicating a greater increase in the SHF than in BRE.In contrast, no significant time group interaction was observed for pelvic posterior tilt angle, even though both groups showed meaningful reductions following the intervention.Conclusion: SHF and BRE effectively improved hip flexion tension and reduced the posterior pelvic tilt angle during the hip flexion task.SHF produced a greater increase in hip flexion tension, suggesting a stronger facilitation of selective iliopsoas activation, whereas BRE also helped improve pelvic alignment through integrated lumbopelvic stabilization.These findings support the clinical use of both exercises based on specific therapeutic goals.