Gender-Based and Bilateral Variations in the Quadriceps Angle and Femoral Bicondylar Distance Among Healthy North Indian Adults: A Cross-Sectional Study

Introduction: The quadriceps angle (Q-angle) and bicondylar distance (ICD) are physical assessments used for knee alignment. Both parameters provide valuable insights into gender-specific and bilateral variations in knee biomechanics that may influence injury risk, functional performance, and degenerative changes throughout adulthood. Materials and methods: This cross-sectional, observational study was conducted to evaluate gender-based variations in the Q-angle and ICD of the femur, comprising 600 participants (300 male participants and 300 female participants), aged 20-50 years, of North Indian origin. The Q-angle was measured using a universal 360° manual goniometer, and the ICD of the femur was measured using a digital Vernier caliper in accordance with standard anthropometric measurement procedures. Results: The average age of male participants was 35.4 ± 9.0 years, while that of female participants was 35.5 ± 8.6 years in the study population. Male participants had a slightly higher mean height (164.8 ± 8.2 cm) and mean body weight (66.6 ± 8.5 kg). Female participants demonstrated significantly higher Q-angle values than male participants (16.53± 5.22 vs 13.85 ± 5.32, p < 0.001), whereas the ICD does not show a significant difference between genders (p = 0.083). Within gender groups, significant right-left differences were observed for the Q-angle. Conclusion: The study provides valuable normative data on the Q-angle and ICD in the adult North Indian population. Female participants showed significantly higher Q-angle values than male participants, while the ICD showed no gender related difference, suggesting that Q-angle and ICD parameters represent distinct aspects of knee alignment and independently contribute to knee biomechanics.