Bilateral Q angle asymmetry and anterior knee pain syndrome

Abstract Objective . To determine whether quadriceps (Q) angles were bilaterally symmetric in individuals asymptomatic vs symptomatic for anterior knee pain. Design . Cross-sectional study. Background . Previous attempts to link excessive Q angles to the occurrence of knee pain have yielded equivocal results. Deriving unilateral rather than bilateral measures of the Q angle and thereafter analysing data using traditional between-group analysis-of-variance structural models may, however, play a role in obscuring the true nature of the Q angle-knee pain relationship. Methods . Left and right Q angles were goniometrically measured in 75 subjects (37 males, 38 females) while they adopted a static, standing position with quadriceps relaxed. The majority ( n = 50) were asymptomatic, while the remainder were unilaterally ( n = 11) or bilaterally ( n = 14) symptomatic for anterior knee pain. A questionnaire was used to determine the extent and magnitude of pain experienced in each of the symptomatic subjects. Results . Significant right vs left lower limb differences in Q angles were observed by group ( p p r = 0.53, p Conclusion . Q angles are not bilaterally symmetric, with the magnitude and direction of the observed asymmetry varying according to whether an individual is asymptomatic, unilaterally symptomatic, or bilaterally symptomatic for anterior knee pain.