Bimanual force coordination in children with spastic unilateral cerebral palsy
B C M Smits-Engelsman1, K Klingels, H Feys
1Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Leuven, Belgium. bouwiensmits@hotmail.com
Insights
Children with unilateral cerebral palsy (CP) exhibit impaired bimanual grip-force coordination, showing slower force generation and reduced synergy between hands during object manipulation tasks.
Area of Science:
- Neurology
- Biomechanics
- Pediatrics
Background:
- Unilateral cerebral palsy (CP) affects motor control, impacting fine and gross motor skills.
- Bimanual coordination is crucial for daily activities, and its impairment can significantly affect individuals with CP.
Purpose of the Study:
- To quantify bimanual grip-force coordination in children with unilateral CP.
- To compare force control mechanisms between children with CP and typically developing (TD) children.
Main Methods:
- Utilized a novel "Gripper" system to record grip and lift forces during a bimanual task.
- Compared 12 children with unilateral CP (aged 5-14) to 23 age-matched TD children.
Main Results:
- Children with CP were significantly slower, taking 50% more time to generate grip and lift forces.
- Reduced coordination between hands was observed in the CP group, with altered force scaling during object separation.
- Impaired pull-hold synergy and increased linearity error in force control were noted in children with CP, particularly under low load conditions.
Conclusions:
- The study reveals significant deficits in bimanual grip-force coordination and force control mechanisms in children with unilateral CP.
- Findings suggest an impaired pull-hold synergy and highlight the utility of bimanual tasks for understanding force control in spastic hands.
Abstract:
In this study bimanual grip-force coordination was quantified using a novel "Gripper" system that records grip forces produced while holding a lower and upper unit, in combination with the lift force necessary to separate these units. Children with unilateral cerebral palsy (CP) (aged 5-14 years, n=12) were compared to age matched typically developing (TD) children (n=23). Compared to TD, the CP-group is much slower and takes 50% more time to generate grip and lift forces with more fixating force before lifting the upper unit. In addition the coordination between forces in both hands is reduced. The CP-group increases the lift force in the upper hand 2.5 times more than the holding force when pulling the two units apart, while this is only 1.5 times in TD. Moreover, the correlation between forces generated in both hands in the CP-group is lower. The lack of fine tuning of the forces, measured by the linearity error is increased, especially when the magnet load keeping the unit together is low. The results indicate an impaired pull-hold synergy between upper and lower hand and the lift force. Bimanual tasks evaluating bimanual grip and lift forces in children with CP and can give us new insights in the underlying force control mechanisms of the spastic hand.
