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BACKGROUND AND AIM: Postural adjustments to an upcoming support-surface perturbation of balance have been shown to be affected by advance knowledge of the amplitude and speed of perturbation [1], which has been contributed to activity of the cerebral cortex [2]. While advance knowledge in one-handed catching has recently been shown to influence the kinematics of the arm when there is certainty about the speed of the ball [3], this study examined how this implicit advance knowledge might also have an effect on postural adjustments. METHODS: 6 skilled ball catchers performed one-handed catches with (blocked-order) and without (random-order) implicit advance knowledge of upcoming ball speed. Measurement of full body kinematics (Qualisys) and kinetics (AMTI force plate) enabled to analyze the postural adjustments while raising the arm for catching. RESULTS: A repeated measures ANOVA analysis showed that providing implicit advance knowledge induced a forward arm raising movement scaled to ball speed in the initial transport phase (p<0.05, Fig. 1a, [3]). However, the accompanying backward postural adjustments were unaffected, which is suggestive of a passive control mechanism. In the subsequent grasping phase (Fig. 1b), the scaling of arm raising movement exhibited in the presence of implicit advance knowledge resulted in a reduced need for postural adjustments, particularly at the highest ball speed (p<0.05). CONCLUSIONS: Advance knowledge of ball speed does not only influence the arm movement kinematics when catching a ball, but seems to have an additional effect on the accompanying postural adjustments to help compensate for the disturbing effect of arm motion. REFERENCES 1. Horak et al. J Neurophysiol. 62:841-853, 1989 2. Jacobs et al. Clin Neurophysiol. 119:1431-1442, 2008 3. Tijtgat et al. Exp Brain Res. 201:875-884, 2010