Geometric features of workspace and joint-space paths of 3D reaching movements

• Published in: Acta psychologica 1998-11, Vol.100 (1), p.37-53
• Main Authors: Klein Breteler, Mary D., Meulenbroek, Ruud G.J., Gielen, Stan C.A.M.
• Format: Article
• Language: English
• Subjects: Activity levels. Psychomotricity; Adult; Biological and medical sciences; Depth Perception - physiology; Female; Fundamental and applied biological sciences. Psychology; Hand; Humans; Image Processing, Computer-Assisted; Joints - physiology; Male; Motor co-ordination; Orientation - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor activities; Psychomotor Performance - physiology; Range of Motion, Articular - physiology; Shoulder; Space life sciences; Workplace
• ISSN: 0001-6918; 1873-6297
• DOI: 10.1016/S0001-6918(98)00024-9

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° 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.