Trunk Kinematics during Pediatric Gait

Abstract

Research on gait development has focused mainly on the mechanics of the lower extremities and as a result, three-dimensional trunk kinematic data in normative pediatric populations is not well documented. Identifying when children achieve mature trunk kinematics is critical to our understanding of normal and pathological gait. Therefore, the purpose of this study is to compare trunk kinematics in mature versus immature walkers. An eight camera Vicon MCam system (Oxford Metrics Group) was used to track the trajectories of reflective markers placed on each subject’s pelvic and trunk segments. Euler angles were computed from the relative orientations of local coordinate systems in each body segment. Principal component analysis was applied to nine kinematic waveform variables (N=9) from each of two age groups (1-4 years (n=25) and 4.5-13 years (n=26). The principal component scores for each kinematic variable were used to test for group differences using one-way ANOVA and Kruskal-Wallis tests. Significant group differences (P<0.05) were found for three of the principal component scores capturing waveform patterns associated with relative trunk rotation and relative and absolute trunk tilt. Compared to the older group, the younger group demonstrated increased relative trunk retraction, decreased anterior trunk tilt, and a posterior trunk tilt relative to the pelvis. The results of this work suggest that there are age-related differences in the ability to coordinate the pelvis and trunk segments during gait. Knowledge of age-specific trunk kinematics may have important implications for rehabilitation programs aimed at improving trunk motion.