Typical and atypical (cerebral palsy) development of unimanual and bimanual grasp planning.
Kids with CP do not outgrow unimanual planning deficits, but bimanual drills can unlock immediate gains.
01Research in Context
What this study did
Janssen et al. (2011) watched kids with cerebral palsy pick up a cube.
They compared grasp height planning in kids with CP and typical kids.
Kids used one hand first, then both hands together.
What they found
Typical kids planned smarter grasps as they grew older.
Kids with CP showed no age gain when using one hand.
Two hands helped a little, but only on the weaker side.
How this fits with other research
Cavézian et al. (2010) saw gains after eight weeks of CIMT plus bimanual play.
Their positive result seems to clash with the null age trend here.
The gap is timing: Loes measured natural growth, Céline measured therapy gains.
Krajenbrink et al. (2019) later repeated the same sword task and also found no age boost.
That double null strengthens the idea that the task itself may be too easy.
Hung et al. (2011) ran a trial of pure bimanual training the same year.
They showed real gains in two-hand timing, proving the idea Loes only hinted at.
Why it matters
If you assess a child with CP and see poor grasp planning, do not wait for maturity to fix it. Add bimanual goals to your next session. Use tasks that demand true coordination, not simple reach-and-grab. Track progress weekly, not yearly.
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02At a glance
03Original abstract
In the present study we tested 13 children with cerebral palsy (CP) and 24 typically developing children (7-12 years old) in a unimanual and bimanual motor planning task. We focused on two research questions: (1) How does motor planning develop in children with and without CP? and (2) Is motor planning facilitated when the task is performed with both hands? Participants had to grasp one or two vertical oriented cylinder(s) and transport it/them to a platform that had different heights. As a measure of motor planning, we registered the height at which participants grasped the cylinder. Here, anticipation of grasp height upon the height of the upcoming target(s) is reflective of proper forward motor planning as it leads to a comfortable posture at the end of the task. In the unimanual task the typically developing children showed a significant grasp height effect, which increased with age. In contrast, no grasp height effect, or age related changes therein were found for the children with CP, suggesting a compromised development of motor planning in these children. Interestingly, when children had to transport one cylinder to a high shelf and one cylinder to a low shelf, the more affected hand of the CP children clearly anticipated the grasp height to the upcoming target height. The less affected hand did not show such anticipation. Taken collectively, these findings suggest a delayed or compromised development of motor planning in children with CP compared to typically developing children. At the same time, the facilitated motor planning of the more affected arm in the bimanual task offers a valuable entry point for intervention to improve motor planning in CP.
Research in developmental disabilities, 2011 · doi:10.1016/j.ridd.2011.02.002