De Freitas, S. M. | Search bioRxiv

bioRxiv2026

Maturation of Gait: Identification of Locomotor Profiles from Early Childhood to Adulthood

BackgroundHuman gait is a key marker of motor development. While walking on even surface is well-documented, responses to irregular surfaces, closer to real-world environments, remain understudied. This limitation is reinforced by the frequent use of univariate analyses, though locomotor control emerges from interactions of multiple features. Multivariate approaches are therefore essential to characterize developmental modulations to uneven surfaces. Objectives(i) To evaluate the combined effects of age and surface complexity on multiple gait domains in healthy individuals during development; (ii) To identify locomotor profiles across gait maturation. MethodsSixty-eight participants (2-35 years) walked at a self-selected speed on even, medium, and high irregularity surfaces. Gait kinematics were captured using a 3D motion system. Linear Mixed Models evaluated age and surface effects on 28 variables across five domains: pace, rhythm, dynamic stability, variability, and asymmetry. Moreover, principal component analysis followed by k-means clustering was performed on 15 normalized variables to identify gait profiles. ResultsAge and surface influenced most variables (p<0.05). Young children (2-5 years) exhibited the greatest modulation of asymmetry, base of support, smoothness, and dynamic stability with surface complexity. Conversely, adults and adolescents (12-35 years) showed higher variability modulation on irregular surface. PCA-assisted clustering identified two clusters: Cluster1 (15.2 years, smooth-regular) and Cluster2 (6.1 years, wide-base-variable). Across surfaces, five subgroups emerged: two consistent (15.8 years in Cluster1; 5.4 years in Cluster2) and three switchers (8.5 years [7.6-12.8]) showing context-dependent transitions as surface complexity increased. DiscussionDifferential maturation and surface sensitivity suggest that irregular surfaces act as functional stressors, revealing developmental gaps hidden on even ground. The surface-dependent transition at 7-13 years suggests that locomotor maturity is task-dependent rather than a fixed state, shifting from stable, regular to a variability-driven, balance-supportive strategy with complexity. These profiles delineate developmental stages and may help to identify atypical trajectories in pediatric rehabilitation.

bioengineering↗

bioRxiv2026

Impact of age and surface irregularities on intersegmental and inter-joint coordination during gait

Uneven walking surfaces require adjustments in motor strategies and can thus provide insights into the neuromuscular changes underlying maturation. Also, coordination metrics and variability offer a richer description of motor control mechanisms than standard spatiotemporal parameters, constituting a more sensitive approach to characterize developmental changes. This study aimed to investigate the effects of uneven surfaces on intersegmental coordination, as well as inter-joint coordination and its variability, and to assess the differences in adaptation between age groups when walking on uneven surfaces. Seventy participants (2-29 years), divided into four age groups, completed gait trials on an even and two levels of uneven surfaces while equipped with reflective markers. Mean absolute relative phase and deviation phase of the knee-hip and ankle-knee joint pairs were computed to characterize lower limb inter-joint coordination and variability. In addition, the organization and density of whole-body intersegmental coordination were assessed using correlation networks built from marker acceleration data. Uneven surfaces induced more in-phase inter-joint coupling, reduced network density and increased variability across all age groups. While the organization of intersegmental coordination remained stable, older participants exhibited denser networks, reflecting refined segmental interactions. In contrast, younger participants showed more in-phase joint coordination and higher variability suggesting less mature motor control. The age-related inter-joint coordination differences were emphasized on uneven surfaces, likely reflecting the maturation-related ability to modulate spinal locomotor patterns via supraspinal control, thereby increasing adaptation to environmental perturbations. Highlights- Uneven surfaces induce more in-phase inter-joint coordination. - Uneven surfaces accentuate differences in locomotor strategies across development. - Kinectome density may be a promising indicator of locomotor maturation. - Coordinative variability decreased with neuromotor development.

physiology↗