title: Effects of task constraints on reaching kinematics by healthy adults.
abstract: Understanding the control of movement requires an awareness of how tasks constrain movements. The present study investigated the effects of two types of task constraints--spatial accuracy (effector size) and target location--on reaching kinematics. 15 right-handed healthy young adults (7 men, 8 women) whose mean age was 23.6 yr. (SD=3.9 yr.) performed the ringing task under six conditions, formed by the crossing of effector size (larger vs smaller size) and target location (left, right, or a central position). Significant main effects of effector size and target location were found for peak velocity and movement time. There was a significant interaction for the percentage of time to peak velocity. The findings suggested that task constraints may modulate movement performance in specific ways. Effects of effector size might be a consequence of feedforward and feedback control, and location effects might be influenced by both biomechanical and neurological factors.
authors.affiliation: Department of Occupational Therapy, Chang Gung University College of Medicine, Tao-yuan.
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Wu
authors.forename: Keh-Chung
authors.initials: KC
authors.lastname: Lin
authors.forename: Kwan-Hwa
authors.initials: KH
authors.lastname: Lin
authors.forename: Chein-Wei
authors.initials: CW
authors.lastname: Chang
authors.forename: Chia-Ling
authors.initials: CL
authors.lastname: Chen
mesh_terms: D000328:Adult; D001364:Awareness; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D009949:Orientation; D010781:Photography; D011597:Psychomotor Performance; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D012858:Size Perception; D013337:Students, Medical / Q000523:psychology; D013624:Taiwan