An Aquatic Treadmill Alters Lower Limb Walking Dynamics in Typically Developing Children and Children with Cerebral Palsy

Abstract

Highlights: What are the main findings? This study showed improved sample entropy measures of the hip, knee, and ankle joints for the children with CP at slower than faster treadmill speeds in the aquatic treadmill compared to a dry treadmill environment. Sample entropy of the typically developing group’s knee and ankle joints improved in the aquatic treadmill environment compared to the dry treadmill. What is the implication of the main finding? The findings imply that the aquatic treadmill environment could improve the walking regularity of children with cerebral palsy. This block-randomized crossover study investigated how a speed-modulated aquatic treadmill (AT) impacts the walking biomechanics of pediatric gait. Eight cerebral palsy (CP) and fifteen typically developing (TD) children walked at normal, slow, and fast treadmill speeds in AT and dry treadmill (DT) conditions. The joint angles of participants were calculated from inertial measurement units to derive sample entropy (SE) measures that quantified the regularity or complexity of motion. A hierarchical statistical model revealed that the CP group had lower SE values for the hip, knee, and ankle joints in the AT and at slower than faster treadmill speeds. Only the SE values of the knee and ankle joints were impacted for the TD group. The lower SE values suggest improved regularity for participants at slower speeds and in the AT environment. This study highlights the potential of AT to improve the walking biomechanics of children with CP in acute exposure, but further work is needed to investigate the AT condition as a gait rehabilitation environment.