Effects of Age and Attentional Focus on the Performance and Coordination of the Sit-to-Stand Task.

This study investigated whether age and attentional focus affect synergy organization of sit-to-stand (STS). Young and older adults performed STS while holding a cup under internal (IF) and external focus (EF) instructions. Uncontrolled manifold analysis was used to decompose trial-to-trial variability in joint kinematics into variability that preserves (V UCM ) and interferes (V ORT ) with the horizontal and vertical positions of the center of mass (CoM) and cup. V UCM was significantly higher than V ORT for all variables in both age groups and focus conditions. Older adults demonstrated higher V UCM for all variables and higher V ORT for all variables except the vertical position of the cup. IF instructions benefited older adults, leading to decreased V ORT of the vertical position of CoM and horizontal and vertical positions of the cup.