title: Control of prehension in hemiparetic cerebral palsy: similarities and differences between the ipsi- and contra-lesional sides of the body.
abstract: This study aimed at broadening our insight into ipsi- and contra-lesional control of prehension after unilateral brain damage. Six male adults with hemiparetic cerebral palsy (mean age 17 years 3 months, SD 15 months) performed unrestricted grasping of discs that differed in size (40, 60, and 80mm in diameter) and which were placed at different distances from the participants (150mm and 30mm). A precalibrated Optotrak 3020 system was used for recording motion. Kinematics of the transport and grasp component, and hand orientation at the moment of grasping, were determined. A marker on the wrist was used to calculate the kinematics of the transport component. The distance between the markers on the index finger and thumb was used for the calculation of the grasp component. Kinematic variables of the transport and grasp component were remarkably similar between both sides of the body. However, with the contra-lesional side, more time was spent in contact with the object before it was lifted, and movements were performed less fluently compared with the ipsi-lesional side. Maximum grasp aperture was attained very late during reaching. For final hand orientation, results showed a large standard deviation both within and between participants. These findings show that, despite the ostensible awkward prehension movements of the contra-lesional side (slowness and decreased fluency), similarities in the kinematics between both sides of the body are present, which may be indicative of intact central control of the movement. The results of variant final hand orientation, combined with the relative late occurrence of peak aperture, suggest that these participants encounter difficulties with forward planning and may use a step-by-step control strategy.
authors.affiliation: Nijmegen Institute for Cognition and Information, Katholieke Universiteit Nijmegen, Nijmegen, the Netherlands. steenbergen@nici.kun.nl
authors.forename: Bert
authors.initials: B
authors.lastname: Steenbergen
authors.forename: John
authors.initials: J
authors.lastname: van der Kamp
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D002547:Cerebral Palsy / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000503:physiopathology; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012858:Size Perception / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013998:Time Perception / Q000502:physiology