Constancy of Preparatory Postural Adjustments for Reaching to Virtual Targets across Different Postural Configurations

Postural and movement components must be coordinated without significant disturbance to balance when reaching from a standing position. Traditional theories propose that muscle activity prior onset create the mechanics counteract internal torques generated by future limb movement, reducing possible instability via centre of mass (CoM) displacement. However, during goal-directed reach movements executed on fixed base support (BoS), preparatory postural adjustments (or pPAs) promote CoM within BoS. Considering this dichotomy, current study investigated if pPAs constitute part whole-body strategy is tied efficient execution rather than constraints balance. We reasoned were primarily control, they would modulate as function perceived instability. Alternatively, dynamics necessary for initiation, remain unchanged, with feedback-based changes being sufficient retain following volitional arm movement. Participants beyond-arm in four different configurations altered quality Quantification these stability did not drastically alter tuning or timing despite modifications trajectories complete In contrast traditional views, always tuned maintenance even calculation upcoming but may reflect requirement voluntary towards pre-defined location.