Trunk and pelvis biomechanical responses in children with cerebral palsy and with typical development during horseback riding.

The research analyzed how horseback riding (HR) affects the biomechanics of children with Cerebral Palsy (CP) and those under normal development. The study provided evidence that HR could potentially improve postural control in children with CP by observing differences in their trunk and pelvis movements during the activity compared to their typically developing peers.

Research Methodology

• To investigate the three-dimensional biomechanical responses of the children, the researchers enlisted a participant pool that consisted of 10 typically developing (TD) children and 10 children with spastic diplegia cerebral palsy (SDCP) – a form of CP that primarily affects lower-body movement. The GMFCS level III indicates that these children were moderately affected by their condition.
• All participant children, aged between 4-12 years, were inexperienced horse riders. This was important to avoid any pre-learned riding skills that may potentially skew the results of the study.
• The researchers used a type of sensor called Inertial Measurement Units (IMU) strapped to the children’s trunks and pelvis, and an additional IMU strapped on the horse’s lumbosacral joint, which enabled them to accurately measure angular displacements and velocities during the horse riding activity.

Data Analysis

• Angular displacements and velocities measurements were processed to calculate the Mean Absolute Relative Phase (MARP) and Deviation Phase (DP) across the horse’s gait cycle for all three planes of movement (frontal, sagittal, and longitudinal).
• Differences between the SDCP and TD children were statistically analyzed using independent t-tests. The t-test is a statistical hypothesis test that helps to determine if there is a significant difference between the means of two groups.

Findings

• The MARP in the frontal plane, which refers to the average phase difference between the children’s movement and the horse’s movement, was lower in the SDCP group compared to the TD group with a statistically significant p-value (p = 0.01). A lower MARP indicates that the movements of the SDCP group were more in-phase, or coupled, relative to the horse’s movements.
• No significant differences were found between the SDCP and TD group for the DP along all three axes. DP is a measure of movement variability, with higher DP indicating more variability in movement timing and pattern.
• The TD group, however, exhibited greater variability in pelvic movement in relation to the horse’s pelvis movement compared to the SDCP group, indicating that the SDCP group’s movement was more consistent.
• The results suggest that during horse riding, children with SDCP exhibit a unique in-phase coupling pattern with decreased variability in pelvic movement in relation to the horse’s pelvis. This may explain the therapeutic potential of horseback riding in improving the postural control of children with CP.