Do children with cerebral palsy change their gait when walking over uneven ground?

Independently ambulant children with Cerebral Palsy (CP) often report balance difficulties when walking in challenging settings. The aim of this study was to compare gait in children with CP to typically developing (TD) children walking over level ground and uneven ground, as an evaluation of dynamic balance. Thirty-four children participated, 17 with CP (10 hemiplegia and 7 diplegia, mean age 10 years) and 17 TD (mean age 10 years 1 month). Three-dimensional kinematic and kinetic data of the lower limbs and trunk were captured during walking over level and uneven ground using Codamotion®. Statistical analysis was performed using a mixed-effects model two-factor Analysis of Variance (Group×Surface). Over both surfaces, children with CP showed increased trunk movement in the sagittal (Group effect, p<0.001) and transverse planes (p<0.001), and increased pelvic movement in the coronal plane (p=0.008), indicating impaired trunk control. Peak separation between the centre of mass and centre of pressure was reduced in CP, indicating impaired dynamic balance (p=0.027). TD children made a number of significant adaptations to uneven ground, including reduced hip extension (mean difference 3.4°, 95% CI [-5.3, -1.0] p=0.006), and reduced ankle movement in the sagittal (5.2°, 95% CI [0.01, 10] p=0.049) and coronal planes (2.4°, 95% CI [0.3, 4.5], p=0.029), but these adaptations were not measured in CP. A significant Group×Surface interaction was detected for knee sagittal range (p=0.009). The findings indicate that children with CP walk show impaired control of trunk movement and are less able to adapt their gait to uneven ground, particularly at the ankle.