Abstract|Neurorehabilitation 2| Volume 357, SUPPLEMENT 1, e89, October 15, 2015

How do the Task Constraints affect the Performance of Aiming Movements after Stroke?

      Background: Discrete and cyclic movements are differentially controlled by the central nervous system, which influences the performance of aiming movements. Direction of movement also influences performance. Cyclic and ipsilateral movements are faster and smoother than discrete and contralateral movements. The effects of task constraints over paretic arm performance were less explored.
      Objective: This study analyzed the influence of the task constraints in paretic arm performance after stroke.
      Method: A cross-sectional study was conducted with 10 post-stroke and 10 healthy individuals. Participants performed aiming movements over a digitizing tablet in different ways: discrete and cyclic movements and for ipsilateral and contralateral direction of the moving limb. The paretic arm was used by all patients. Temporal (reaction time, movement time and peak velocity) and spatial (smoothness, trajectory length and resultant constant error) variables were analyzed. Analysis of variance was used considering a significance level of 5%.
      Results: Patients were slower to react and less smooth and accurate than the healthy group. Cyclic and ipsilateral movements were faster and less accurate than the discrete and contralateral movements for both groups. Additionally, patients could not reach the same trajectory length of the healthy group in cyclic movements.
      Conclusion: Individuals after stroke modulate the paretic arm performance according to the task constraints similarly to that of healthy individuals. Both groups prioritized accuracy in discrete movements and speed in cyclical movements and were faster and smoother in the ipsilateral direction. Cyclic movements were, however, more difficult to be completed by the paretic arm.