title: Geometric features of workspace and joint-space paths of 3D reaching movements.
abstract: The present study focuses on geometric features of workspace and joint-space paths of three-dimensional reaching movements. Twelve subjects repeatedly performed a three-segment, triangular-shaped movement pattern in an approximately 60 degrees tilted horizontal plane. Task variables elicited movement patterns that varied in position, rotational direction and speed. Trunk, arm, hand and finger-tip movements were recorded by means of a 3D motion-tracking system. Angular excursions of the shoulder and elbow joints were extracted from position data. Analyses of the shape of 3D workspace and joint-space paths focused on the extent to which the submovements were produced in a plane, and on the curvature of the central parts of the submovements. A systematic tendency to produce movements in a plane was found in addition to an increase of finger-tip path curvature with increasing speed. The findings are discussed in relation to the role of optimization principles in trajectory-formation models.
authors.affiliation: Department of Experimental Psychology, University of Nijmegen, The Netherlands. kleinbreteler@nici.kun.nl
authors.forename: M D
authors.initials: MD
authors.lastname: Klein Breteler
authors.forename: R G
authors.initials: RG
authors.lastname: Meulenbroek
authors.forename: S C
authors.initials: SC
authors.lastname: Gielen
mesh_terms: D000328:Adult; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007596:Joints / Q000502:physiology; D008297:Male; D009949:Orientation / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D014741:Video Recording; D017132:Workplace