Relationships between knee and hip adduction moment, static leg torsion and dynamic frontal and transversal plane gait parameters in children and adolescents.

BACKGROUND

Knee adduction moment and hip adduction moment are widely used indicators of joint loading and are related to osteoarthritis, but the impact of transverse plane parameters on these moments remains underexplored. Therefore, this study investigated the relationship between computed tomography-based measurements of static lower limb torsion and dynamic frontal and transverse plane gait patterns with knee and hip adduction moments in children and adolescents.

METHODS

Gait analysis data (knee and hip adduction angles/moments, hip and knee rotation, foot progression, step width, walking speed, body mass index) and computed tomography-based leg torsion variables (femoral anteversion, tibial torsion) were retrospectively analyzed in 147 patients (13.2 ± 1.6 years). Pearson and semi-partial correlations, accounting for collinearity, were conducted using statistical parametric mapping.

FINDINGS: Accounting for collinearity, knee adduction (rmax = 0.69), foot progression in terminal stance (rmax = 0.34), and walking speed in midstance (rmax = -0.31) were the strongest predictors of knee adduction moment. Hip adduction moment was most associated with walking speed in midstance (rmax = -0.65) and hip adduction in preswing (rmax = 0.40). Hip and knee rotation, femoral anteversion, tibial torsion, step width, and body mass index showed initial correlations but lost significance when collinearity was considered.

INTERPRETATION: Transverse plane variables indirectly relate to knee and hip frontal plane moments. Knee adduction, foot progression, and walking speed are more directly related to knee adduction moment, while hip adduction and walking speed are related to hip adduction moment. Future studies should examine mediating effects when investigating joint moment determinants.