Visual guidance during an interception task in children with Spastic Hemiparetic Cerebral Palsy
P M van Kampen1, A Ledebt, G J P Savelsbergh
1Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University, UK. p.vankampen@mmu.ac.uk
Insights
Children with Spastic Hemiparetic Cerebral Palsy (SHCP) adjusted walking speed to intercept moving balls. However, impaired hand use led to less successful trials and greater deviations from typical movement strategies.
Area of Science:
- Neuroscience
- Biomechanics
- Developmental Psychology
Background:
- Spastic Hemiparetic Cerebral Palsy (SHCP) affects motor control, impacting daily activities like object interception.
- Understanding gait adjustments in children with SHCP is crucial for developing effective rehabilitation strategies.
- The bearing angle (BA) strategy is a key model for analyzing visually guided interception tasks.
Purpose of the Study:
- To investigate gait adjustments in children with SHCP during a moving ball interception task.
- To determine if children with SHCP maintain a constant bearing angle (BA) during interception.
- To assess the influence of impaired vs. less-impaired hand use on interception success and gait strategy.
Main Methods:
- Children with SHCP intercepted balls from a conveyor belt at varying velocities and orientations.
- Participants walked from a fixed distance, with trials involving impaired or less-impaired hand grasps.
- Gait velocity, ball velocity, and bearing angle (BA) variations were analyzed throughout the interception trajectory.
Main Results:
- Walking velocity was adjusted in response to ball velocity.
- Children using their impaired hand showed initial faster movement followed by significant deceleration near the belt.
- Less variation in BA was observed with the less-impaired hand or increased ball velocity, suggesting some strategy adaptation.
Conclusions:
- Children with SHCP demonstrate an ability to adjust walking behavior in response to task demands, indicating awareness of their impairment.
- Gait adjustments were not fully sufficient to compensate for the reduced reaching ability of the impaired hand.
- Deviations from a constant BA were more pronounced when using the impaired hand compared to the less-impaired hand, especially when compared to typically developing children.
Abstract:
The aims of the study are to determine the presence of adjustments in walking behaviour of children with Spastic Hemiparetic Cerebral Palsy (SHCP) during the interception of a moving ball and, whether the angle between the ball and the participant is kept constant. This would support the use of the so-called bearing angle (BA) strategy in interception of the object. Children with left hemisphere damage intercepted a ball from a conveyor belt at three different velocities, from a frontal or lateral orientation and with their impaired or less-impaired hand. The participants walked from a distance of 4m perpendicularly to the belt. Children seemed to have less successful trials when grasping with the impaired hand. The results showed that the walking velocity was adjusted to the ball velocity. When they grasped with the impaired hand, children initially moved faster to the interception point, while closer to the belt significant slower. The BA showed less variation over the trajectory when the children grasped with their less-impaired hand or when the ball velocity increased. It was concluded that children with SHCP were able to take their impairment into account as indicated by adjustments in walking behaviour. However, these adjustments in walking velocity were not sufficient to compensate totally for the limited reaching ability in the impaired hand. As a result of these adjustments, the amount of variation from the constant BA seemed to deviate more from typically developing children when grasping with impaired hand than when grasping with less-impaired hand.
