title: Adaptive motor behavior of cerebellar patients during exposure to unfamiliar external forces.
abstract: The authors investigated adaptation of goal-directed forearm movements to an unknown external viscous force assisting forearm flexion in 6 patients with cerebellar dysfunction and in 6 control participants. Motor performance was generally degraded in cerebellar patients and was markedly reduced under the force condition in both groups. However, patients and controls were able to adapt to the novel force within 8 trials. Only the healthy controls were able to improve motor performance when readapting to a null-force condition. The results indicate that cerebellar patients' motor control system has imprecise estimations of actual limb dynamics at its disposal. Force adaptation may have been preserved because single-joint movements were performed, whereas the negative viscous force alone and no interaction forces had to be compensated.
authors.affiliation: University of Düsseldorf and University of Essen, Germany. s.richter@uni-essen.de.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Richter
authors.forename: Matthias
authors.initials: M
authors.lastname: Maschke
authors.forename: Dagmar
authors.initials: D
authors.lastname: Timmann
authors.forename: Jürgen
authors.initials: J
authors.lastname: Konczak
authors.forename: Tobias
authors.initials: T
authors.lastname: Kalenscher
authors.forename: Anton R
authors.initials: AR
authors.lastname: Illenberger
authors.forename: Karl- Theodor
authors.initials: K
authors.lastname: Kalveram
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D000368:Aged; D002526:Cerebellar Diseases / Q000175:diagnosis / Q000503:physiopathology*; D002531:Cerebellum / Q000502:physiology; D004551:Elbow Joint / Q000294:innervation*; D005260:Female; D005542:Forearm / Q000294:innervation*; D006040:Goals; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D011214:Practice, Psychological; D011434:Proprioception / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D016474:Weight-Bearing / Q000502:physiology*