Importance: Motor planning refers to the ability to anticipate actions and predict motor outcomes before execution. Deficits in motor planning, rather than just execution, contribute to activity limitations in children with unilateral cerebral palsy (CP). However, the differences in motor planning between the two hands of children with unilateral CP in unimanual and bimanual conditions remain underexplored. Objective: To investigate the differences in motor planning skills between the less affected and more affected hands of children with unilateral CP and both hands of age-matched typically developing (TD) children across unimanual, bimanual symmetric, asymmetric, and functional tasks. Design: Cross-sectional study. Setting: University laboratory. Participants: Twenty children with unilateral CP and 20 age-matched TD children. Outcomes and Measures: Motor planning task performance was assessed using the end-state comfort (ESC) effect, measured by cup–bottle tasks. Results: Children with unilateral CP demonstrated lower motor planning ability in their more affected hand compared with their less affected hand. Significant ESC differences were found across task conditions for children with CP, with the best performance observed in functional bimanual tasks. Additionally, the less affected hand demonstrated poorer motor planning in symmetrical tasks, possibly influenced by the performance of the more affected hand. Conclusions and Relevance: This study highlights differences in motor planning ability between the hands of children with unilateral CP, emphasizing the impact of task type and hand dominance. Functional bimanual tasks improved motor planning, underscoring their value in interventions. Future assessments and training should address both hands and incorporate functional tasks to enhance motor planning in children with unilateral CP. Plain-Language Summary: Motor planning is the capacity to anticipate upcoming actions and organize each step in advance, enabling tasks to be performed smoothly and accurately. This study adds new insights into motor planning differences between the less affected and more affected hands of children with unilateral cerebral palsy. Unlike typically developing children, who demonstrate balanced motor planning between both hands, children with unilateral cerebral palsy showed significant disparities, with the more affected hand performing notably worse. The study also underscores the importance of considering both hands in assessments, as focusing solely on the less affected hand fails to provide a comprehensive understanding. Furthermore, the findings highlight that functional bimanual tasks improve motor planning in children with unilateral cerebral palsy, suggesting that task context is critical in motor planning performance. Finally, study results reveal that bimanual tasks, particularly under symmetric conditions, can lead to negative interactions between the hands, where the less affected hand tends to mimic the inefficient movements of the more affected hand, diminishing motor planning performance. These findings emphasize the need for individualized, task-specific interventions that address both hands to enhance motor planning and promote more balanced motor functioning in children with unilateral cerebral palsy.
Liu et al. (Thu,) studied this question.