This study aimed to analyze gait termination strategies in children with CP compared to typically developing (TD) children, focusing on two different stopping distances.
The participants included 12 children with CP (mean age: 12.3 years, six females; mean height: 146.8 cm; mean weight: 40.2 kg) and 10 TD children (mean age: 11.4 years, nine females; mean height: 142.0 cm; mean weight: 38.1 kg). Virtual reality software Vizard (WorldViz, Santa Barbara, CA, USA) was used in conjunction with Vicon Nexus (Vicon Motion System, Oxford, UK), an eight-camera OptiTrack system (NaturalPoint, Corvallis, OR, USA), and four projectors (RICOH PJ WX4153N, RICOH JP) to display a green target line for guiding walking speed and a red stop line for gait termination. Participants were instructed to walk at their comfortable speed and stop in front of a red line, which appeared at either a long (1.75 × leg length) or short (1.5 × leg length) distance from the pelvis marker. Biomechanical parameters were evaluated using three-dimensional motion analysis and force-plate data. Normality was assessed using the Shapiro–Wilk test, and Student’s t-test or Mann–Whitney U test was used to compare the CP and TD groups. Paired t-tests or Wilcoxon signed-rank tests were used to compare the conditions within groups. Statistical significance was set at P 0.05.
The TD group exerted a more pronounced braking force during the first step after the stop line appeared, continuing until the contralateral step, for both long (P 0.001) and short (P = 0.002) distances. The CP group showed reduced minimum force vector angles when exerting braking force for both long (P = 0.028) and short (P = 0.045) distances. Furthermore, these angles emerged earlier in the TD group compared to the CP group for both long (P 0.001) and short (P 0.001) distances. In contrast, the difference in minimum force vector angle time between the long and short conditions was greater in the CP group compared to the TD group (P = 0.021). Additionally, the center of mass (COM) and center of pressure (COP) divergence in the anterior-posterior direction increased in the TD group for both long (P = 0.035) and short (P = 0.011) distances.
Children with cerebral palsy demonstrate complex adaptations during gait termination, compensating for reduced braking function, such as decreased COM and COP divergence and force vector angle, by exerting braking forces earlier. These results suggest that gait interventions should consider dynamic balance strategies and adaptations in braking force timing to prevent collisions during walking in children with cerebral palsy.
These results highlight the importance of considering distinctive braking force exertion and dynamic balancing strategies in gait interventions for children with CP to enhance safety and reduce collision risks.
force vector angle
COP
