Performance Indicators.

Performance indicators at the end of the adaptation phase (last two target-sets) for the stabilization in the central target area. SSI (Stiffness Size Index): Kxx/Ku. SOI (Stiffness Orientation Index): the orientation of the major axis of the stiffness ellipse. BSI (Bimanual Separation Index): average distance between the two hands [cm]. BF (Burst Frequency): [impulses/s]. E (Effort): [N]. CE (Cumulative Effort): [Ns]. STR (Stabilization strategy label): SSS/PSS (subjects were classified as users of the SSS or PSS strategy, based on their average behavior during the last two target sets at the central target.