THE ROLE OF ANTICIPATORY POSTURAL ADJUSTMENTS DURING WHOLE-BODY FORWARD REACHING MOVEMENTS

THE purpose of this study was to examine the role of anticipatory post ural adjustments (APAs) in the execution of forward oriented whole bod y reaching movements. From the standing position, eight healthy subjec ts were asked to reach an object placed at 45 cm from the feet, at bot h naturally paced and fast speeds. Electromyographic signals of six an tagonistic muscles were analysed in conjunction with centre of mass (C M) displacements, centre of foot pressure displacements and resultant ground reaction forces. Results revealed that APAs created necessary a ngular momentum of body segments for effective task execution. These r esults suggest that APAs can initiate movements conducted from a fixed base of support, and in this context do not act solely to stabilize t he CM. (C) 1998 Rapid Science Ltd.