title: Faster Reaching in Chronic Spastic Stroke Patients Comes at the Expense of Arm-Trunk Coordination.
abstract: BACKGROUND
  The velocity of reaching movements is often reduced in patients with stroke-related hemiparesis; however, they are able to voluntarily increase paretic hand velocity. Previous studies have proposed that faster speed improves movement quality.
  
  
  OBJECTIVE
  To investigate the combined effects of reaching distance and speed instruction on trunk and paretic upper-limb coordination. The hypothesis was that increased speed would reduce elbow extension and increase compensatory trunk movement.
  
  
  METHODS
  A single session study in which reaching kinematics were recorded in a group of 14 patients with spastic hemiparesis. A 3-dimensional motion analysis system was used to track the trajectories of 5 reflective markers fixed on the finger, wrist, elbow, acromion, and sternum. The reaching movements were performed to 2 targets at 60% and 90% arm length, respectively, at preferred and maximum velocity. The experiment was repeated with the trunk restrained by a strap.
  
  
  RESULTS
  All the patients were able to voluntarily increase reaching velocity. In the trunk free, faster speed condition, elbow extension velocity increased but elbow extension amplitude decreased and trunk movement increased. In the trunk restraint condition, elbow extension amplitude did not decrease with faster speed. Seven patients scaled elbow extension and elbow extension velocity as a function of reach distance, the other 7 mainly increased trunk compensation with increased task constraints. There were no clear clinical characteristics that could explain this difference.
  
  
  CONCLUSIONS
  Faster speed may encourage some patients to use compensation. Individual indications for therapy could be based on a quantitative analysis of reaching coordination.
authors.affiliation: Raymond Poincaré Hospital, Garches, France GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, UVSQ, Garches, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Mandon
authors.affiliation: GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, UVSQ, Garches, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Boudarham
authors.affiliation: Raymond Poincaré Hospital, Garches, France GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, UVSQ, Garches, France.
authors.forename: Johanna
authors.initials: J
authors.lastname: Robertson
authors.affiliation: Raymond Poincaré Hospital, Garches, France GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, UVSQ, Garches, France.
authors.forename: Djamel
authors.initials: D
authors.lastname: Bensmail
authors.affiliation: Raymond Poincaré Hospital, Garches, France GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, UVSQ, Garches, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Roche
authors.affiliation: GRCTH, EA4497, CIC-IT 805, CHU Raymond Poincaré, UVSQ, Garches, France CNRS, UMR 7222, ISIR, Paris, France Sorbonne Universités, UPMC University Pierre et Marie Curie, UMR 7222, Paris, France INSERM, U1150, Agathe-ISIR, Paris, France roby-brami@isir.upmc.fr.
authors.forename: Agnès
authors.initials: A
authors.lastname: Roby-Brami
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D002908:Chronic Disease; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D009128:Muscle Spasticity / Q000503:physiopathology*; D020521:Stroke / Q000503:physiopathology*; D060726:Torso / Q000503:physiopathology*
keywords: coordination; elbow; hemiparesis; kinematics; trunk