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 (VUCM) and interferes (VORT) with the horizontal and vertical positions of the center of mass (CoM) and cup. VUCM was significantly higher than VORT for all variables in both age groups and focus conditions. Older adults demonstrated higher VUCM for all variables and higher VORT for all variables except the vertical position of the cup. IF instructions benefited older adults, leading to decreased VORT of the vertical position of CoM and horizontal and vertical positions of the cup.