Clinical Utility of Functional Muscle Screening and Objective Postural Tools for Identifying Lower Cross Syndrome: A Randomized Single-Blind Study

Background: Lower Cross Syndrome (LCS) features tight hip flexors and lumbar extensors with weak abdominals and gluteals, producing anterior pelvic tilt and lumbar hyperlordosis. Routine diagnosis often relies on subjective appraisal; pragmatic protocols integrating functional screens with objective postural tools are needed. Objective: To evaluate the responsiveness, clinical utility, and feasibility of a standardized screening protocol that combines functional muscle tests with flexicurve- and inclinometer-based postural measures in adults with LCS. Methods: Randomized, single-blind, parallel-group measurement study at a tertiary outpatient clinic. Adults (n=34; 20–50 years) with anterior pelvic tilt and hyperlordosis and positive baseline functional screens (Modified Thomas, Prone Hip Extension, Trunk Flexion Strength, Side-Lying Hip Abduction) were randomized 1:1 to Bruegger’s or Egoscue exercises for 4 weeks (12 supervised sessions). Functional screens (binary) and objective measures—flexicurve-derived lordotic index (degrees) and pelvic inclinometer angle (degrees)—were recorded pre/post by blinded assessors. Primary endpoint was within-group change in flexicurve; inclinometer and functional screens were secondary; between-group comparisons of change were exploratory. Results: All 34 participants completed follow-up. Functional screens converted from positive to negative in every participant. Flexicurve means improved substantially in both groups (Bruegger: 74.5→59.3; Δ=−15.2; standardized change dav=−1.18dₐᵥ=-1.18dav​=−1.18; Egoscue: 82.5→67.5; Δ=−15.0; dav=−0.90dₐᵥ=-0.90dav​=−0.90). Pelvic tilt decreased by ~3° (Bruegger: 12.5°→9.7°; Δ=−2.8°; Egoscue: 13.1°→10.1°; Δ=−3.0°). Exploratory between-group effects on change were trivial, indicating responsiveness was robust to exercise type. 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.