Effects of Environmental Perturbations on Multijoint Gait Dynamics: A Multidimensional Recurrence Quantification Approach

Quantitative characterization of gait variability and stability is commonly used in the analysis of human locomotion. Multidimensional Recurrence Quantification Analysis is a recurrence‑based approach that operates directly on multivariate time series and does not require reconstruction of phase space through time‑delay embedding. The primary objective of this study was to determine and compare the values of Multidimensional Recurrence Quantification Analysis measures derived from gait data representing sagittal-plane joint angles of the lower limbs and pelvis. Data were recorded in the CAREN Extended environment under two experimental conditions: unperturbed gait and gait with externally induced mechanical perturbations. The study group consisted of fourteen young women. Statistical analyses were performed on the computed Multidimensional Recurrence Quantification Analysis measures, including an evaluation of effect sizes for the observed differences. The results demonstrated that Multidimensional Recurrence Quantification Analysis effectively distinguishes natural gait patterns from gait subjected to externally induced mechanical perturbations.