Sex differences and bilateral symmetry in gait parameters of healthy young adults: establishing a reference model for clinical assessment

To establish quantitative reference values for gait parameters in healthy young adults, examine sex differences and bilateral symmetry, and validate their utility for detecting gait abnormalities in patients with lower limb injuries. Four hundred ninety-one healthy young adults underwent comprehensive gait analysis using a three-dimensional motion-capture system. Individuals with musculoskeletal injuries (identified through GRF distribution and questionnaires) and foot deformities (detected by three-dimensional scanning) were excluded. Spatiotemporal parameters, GRFs, and center-of-mass kinematics and kinetics were analyzed. Bilateral symmetry was assessed, gait parameters were compared between sexes, and reference values were tested in two patients with lower limb injuries. Significant sex differences were observed in gait parameters (P < 0.01), while bilateral symmetry was maintained in all parameters for both sexes. GRF patterns differed between sexes: the first peak occurred at 15.3% of the gait cycle in males versus 29.6% in females, while the second peak occurred at 48.0% in both sexes and consistently exceeded the first peak. Injured patients showed uneven movement between their left and right legs, while healthy people moved symmetrically. Healthy adults display different gait patterns between men and women, but both maintain balanced left-right movement. These sex-based standards can help diagnose musculoskeletal problems and track recovery. Comparing patients to the symmetrical patterns of healthy people helps identify gait abnormalities.