title: Children's catching performance when the demands on the postural system is altered.
abstract: In many dynamic interceptive actions performers need to integrate activity of manual and postural subsystems for successful performance. Groups of different skill level (poor and good catchers), (mean age = 9.1 and 9.4 respectively) were required to perform one-handed catches under different postural constraints: standing; standing in contact with a postural support aid by their side (PSAS) or to the left of their trunk (PSAF); Tandem; and sitting (control). Results revealed that, for poor catchers, the number of successful catches increased and grasp errors decreased significantly when sitting and with both postural aids in comparison with standing alone and Tandem conditions. Kinematic analyses showed that the postural aid devices reduced head sway in the anterior-posterior direction, while the PSAF reduced lateral head sway. The poor catchers' performance benefited from an enlarged support surface, and reduction of lateral sway. Good catchers performed successfully under all task constraints, signifying the existence of a functional relationship between postural and grasping subsystems during performance. The results are discussed in the frame of Bernstein's (1967) and Newell's (1986) theory.
authors.affiliation: Dept. of Sport Science and Physical Education, Aristotle University of Thessaloniki, Greece.
authors.forename: Georgios T
authors.initials: GT
authors.lastname: Angelakopoulos
authors.forename: Haralambos
authors.initials: H
authors.lastname: Tsorbatzoudis
authors.forename: George
authors.initials: G
authors.lastname: Grouios
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology*; D002648:Child; D006225:Hand; D018737:Hand Strength; D006257:Head; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*