Lower Limb Asymmetry in Adolescent Gait: A Cross-Sectional Study of Walking, Running, and Turning with Insights for Promoting Lifelong Physical Activity

Background: Even in healthy individuals, inter-limb asymmetry may influence locomotor efficiency, balance, and injury susceptibility. Turning movements place greater demands on bilateral coordination than straight-line locomotion. This study aimed to examine left–right asymmetry in lower extremity joint motion and mechanical function in adolescents during multiple locomotor tasks. Methods: Fifteen right-leg-dominant male adolescents (age: 15.4 ± 1.05 years; height: 160.62 ± 6.13 cm; body mass: 50.82 ± 5.28 kg) performed four tasks at self-selected speeds: straight walking, straight running, walking with turning, and running with turning. Three-dimensional kinematics were captured using a Vicon system, while ground reaction forces were simultaneously recorded with Kistler force platforms. Kinematic and kinetic data were filtered in MATLAB and processed in OpenSim. One-dimensional statistical parametric mapping was used to identify inter-limb differences across the entire stance phase. Results: Significant left–right differences in ankle, knee, and hip kinematics and kinetics were observed across all tasks. Running exhibited larger and more prolonged asymmetries than walking. Turning tasks amplified asymmetry further, particularly at the knee and ankle, while hip differences were most pronounced during running. Asymmetries were most evident in the ankle during early and mid-stance, in the knee across the majority of the turning stance, and in the hip throughout the running stance. Conclusions: Interlimb asymmetry was task-dependent, with greater differences in running than walking and further amplification during turning. These findings provide insight into lower limb motor control during demanding locomotor tasks and may inform injury prevention, rehabilitation, and the design of sport-related training programs. Highlights Left–right asymmetries in ankle, knee, and hip kinematics were present across all tasks, with prolonged asymmetry in running than walking and further amplification during turning. Asymmetry was joint- and phase-specific: hip asymmetry was nearly continuous during running stance, while ankle (early–mid stance) and knee (most of stance) asymmetries were most pronounced during turning tasks.