Analysis of center of mass and center of pressure displacement in the transverse plane during gait termination in children with cerebral palsy

Background: While gait termination is challenging for children with spastic cerebral palsy (CCP), few studies have quantitatively assessed this issue. Research question: What are the characteristics of center of mass (COM) and center of pressure (COP) displacement during gait termination in CCP, and how do they compare with those in children with typical development (CTD)? Methods: This cross-sectional study included 13 adults with typical development (19.85 +/- 0.52 years), 12 CTD (10.41 +/- 2.98 years), and 16 CCP (11.15 +/- 2.71 years). Participants were instructed to immediately stop walking when a stop sign appeared on a screen, which was placed at the end of an 8-m walkway. COM and COP were determined via 3-dimensional motion analysis and force plate data. Differences between the groups were assessed using the two sample t-test or Wilcoxon rank sum test. The level of statistical significance was set at P < 0.05. Results: The normalized time for stopping in CCP (4.556 +/- 0.602) was higher than that in CTD (3.617 +/- 0.545, P < 0.001). The normalized COP displacement (P < 0.001) and divergence between COM and COP (P < 0.001) in the mediolateral (ML) direction were significantly higher in CCP than CTD. However, the normalized divergence between COM and COP in the anteroposterior (AP) direction in CCP was lower than that in CTD (P = 0.034). Significance: The more minor divergence between COM and COP in the AP direction and the more significant COP displacement in the ML direction cause difficulty to exert braking force during gait termination. Thus, CCP require a longer time for gait termination. This finding may facilitate the development of interventions for improving gait in CCP.