Spatio-temporal parameters of turning in healthy children

Abstract

Introduction: Turning while walking is a crucial part of locomotion, however little is known about the biomechanics of turning maneuvers. The aim of this study was to identify the adaptations required for healthy children to navigate turns. Patients/materials and methods: Thirty-one healthy children performed barefoot walking in a straight line and 90◦ turns at self-selected veolcity. Seventeen children (12 girls, 12.6±2.3 years, height 1.6±0.1m, and leg length 0.8±0.1 m) independently chose to perform turning with both the inside (spin) and outside (step) foot, andwere retained for statistical analysis. Three turning phases were analyzed (approach, turn, and depart strides) while left and right trialswere pooled. Retroreflectivemarkerswere used to automatically detect foot strike and foot off events [1] required to compute spatio-temporal data [2]. Spatial data were normalized to leg length while absolute temporal variables were reported [3]. One-way repeated measures ANOVA with Bonferroni correction were performed on stride velocity, stance time, stride length, and stride width. Results: Half of all children turned utilizing only the spin strategy while no child solely attempted step turns. Statistical analysis revealed that both turning conditions were different from straight walking. Themain differences occurred between turning phases for step and spin conditions while only a few differences were found between turning types (Table 1). Mean [95% confidence interval]. Superscripts indicate statistical difference from straight (*), approach stride same condition (a), turn stride same condition (t), and between conditions for the same phase (s). Discussion and conclusions: The present cohort preferred turning using an inside foot strategy regardless of an increased risk of fall and increasedmuscular demand previously reported [4] and decreased stride width found here. However, it remains unclear how other populations, such as childrenwith cerebral palsy, would perform turning maneuvers. Investigation of turning may provide greater insight into the biomechanical adaptations required for independent ambulation and may lead to the development of more functional rehabilitative programs and improved surgical outcomes.