Clinical Utility of Functional Muscle Screening and Objective Postural Tools for Identifying Lower Cross Syndrome: Evidence from a Randomized Clinical Trial

Abstract

Background: Lower Cross Syndrome (LCS) involves muscle imbalances with tight hip flexors and lumbar extensors alongside weak abdominals and glutei, leading to anterior pelvic tilt and hyperlordosis. Early recognition is essential, yet standardized protocols combining functional and postural assessments remain limited. Objective: To evaluate the responsiveness, usage feasibility, and functional utility of a standardized screening protocol that combines functional muscle assessments with objective postural measures in individuals with LCS. Methods: A randomized Clinical trial was conducted on 34 participants with anterior pelvic tilt and lumbar hyperlordosis. Functional screening included the Modified Thomas, Prone Hip Extension, Trunk Flexion Strength, and Side-Lying Hip Abduction tests. Postural deviations were measured using a pelvic inclinometer and flexicurve ruler. Participants were randomized to receive either Bruegger’s or Egoscue exercises for four weeks (12 supervised sessions). The interventions were used as change-inducing strategies to test the sensitivity of the tools. Pre–post changes were analyzed using parametric or non-parametric tests. Results: All functional tests turned negative post-intervention, confirming restored muscle balance and demonstrating tool sensitivity. Flexicurve scores improved significantly (Bruegger’s: 74.6 → 59.3, d = 1.72; Egoscue: 82.5 → 67.6, d = 1.46; p < 0.001). Pelvic inclinometer readings showed slight improvements within groups (Bruegger’s: 12.5 → 9.7; Egoscue: 13.1 → 10.1), but these changes were not statistically significant (p > 0.05). Between-group differences were non-significant, supporting the robustness of these tools across interventions. Conclusion: The findings indicate that a combined protocol integrating functional muscle assessments with flexicurve and pelvic inclinometer measures offers a reliable, responsive, and practical approach for evaluating Lower Cross Syndrome. Significant improvements in functional balance and flexicurve readings highlight the sensitivity of these tools in detecting postural correction, while inclinometer findings suggest potential for further refinement. Overall, this standardized assessment framework can enhance early detection, individualized intervention planning, and outcome monitoring in both clinical and research settings.