Effect of task constraint on reaching performance in children with spastic diplegic cerebral palsy.
Sideways reaching taxes weak trunk control in spastic diplegic CP—keep important items straight ahead or stabilize the trunk.
01Research in Context
What this study did
The team watched kids reach for toys. Some kids had spastic diplegic CP. Some kids were typically developing.
Each child reached straight ahead, out to the side, and across the body. Cameras tracked hand speed and path.
What they found
Reaching sideways made movements slower and wobblier for kids with CP. Straight-ahead reaches were smoother.
The farther the arm moved sideways, the more the trunk wobbled, and the longer the trip took.
How this fits with other research
Angsupaisal et al. (2017) extends this idea. They tilted seats forward 15°. Kids with unilateral CP reached better, but kids with bilateral CP reached worse. Both papers show trunk position changes arm control.
Ballaz et al. (2014) found the same kids struggle to shift weight side-to-side on a Wii Fit board. Together the studies say lateral trunk control is a weak spot in spastic diplegia.
Hung et al. (2012) saw similar slow, curved reaches in hemiplegia during a reach-grasp-eat task. The movement flaws look alike across CP types.
Why it matters
When you ask a child with spastic diplegic CP to reach sideways, expect extra trunk sway and missed targets. Place toys within easy forward range or add trunk support. Save lateral practice for times when accuracy is not critical.
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02At a glance
03Original abstract
The purposes of the study were to examine the effect of task constraint on the reaching performance in children with spastic cerebral palsy (CP) and to examine the correlations between the reaching performance and postural control. Eight children with CP and 16 typically developing (TD) children participated in the study. They performed a reach-and-return task with a seated posture on a stool. The target for reaching was set at a 120% arm-length distance in three directions (anterior, medial, and lateral). Reaching speed was modulated with a metronome at a rate of 46 beats/min. A motion analysis system recorded the kinematic data of reaching at a sampling rate of 150 Hz. Postural control was assessed with a pediatric reaching test. Movement time (MT), straightness ratio (SR), hand peak velocity (PV), and movement unit (MU) of reaching were compared between groups and among task conditions with repeated measure ANOVAs. Pearson's product-moment correlation coefficients were used to examine the correlations between reaching and postural control. Children with CP presented longer MT, larger SR and more MU than did TD children. Further, the children with CP showed larger SR while reaching medially and laterally than anteriorly. But TD children were not affected by these task constraints. Moderate correlations between postural control ability and SR and MU were noted. In conclusion, the children with CP showed a slower, more skewed, less efficient and less coordinated pattern of reaching than the TD children. Reaching laterally and medially seemed to impair the reaching performance (more skewed and less efficient) of the children with CP, but not of the TD children. Reaching laterally and medially may involve trunk rotation which produces more postural challenges than reaching anteriorly. This finding may explain the difference in the effect of task constraint on hand reaching performance between the two groups of children. Moreover, the better the postural control ability, the straighter, and more efficient and coordinated reaching performance the children showed.
Research in developmental disabilities, 2010 · doi:10.1016/j.ridd.2010.04.001