Ipsilesional arm reaching movements are not affected by the postural configuration adopted by individuals with stroke.

Individuals with stroke present several impairments in the ipsilesional arm reaching movements that can limit the execution of daily living activities. These impairments depend on the side of the brain lesion. The present study aimed to compare the arm reaching movements performed in sitting and standing positions and to examine whether the effects of the adopted posture configuration depend on the side of the brain lesion.

Preparation to a quick whole-body action: control with referent body orientation and multi-muscle synergies.

We examined the control of postural stability in preparation to a discrete, quick whole-body sway toward a target and back to the initial position. Several predictions were tested based on the theory of control with referent body orientation and the notion of multi-muscle synergies stabilizing center of pressure (COP) coordinate. Healthy, young adults performed fast, discrete whole-body motion forward-and-back and backward-and-back under visual feedback on the COP.

Target height affects the symmetry of the postural adjustments after (but not prior) the onset of reaching movements in upright standing.

The present study aimed to investigate the influence of target height on the symmetry and amplitude of the postural adjustments assessed by the displacements of the center of pressure (COP) before and during the unilateral, arm movements in the upright position. Thirteen young, right-handed adults stood with each foot on one force platform and reached a target placed at one of three heights displayed on a monitor screen. The performance of the right arm movements (movement time and radial error), amplitude of the COP displacements of each lower limb and the percentage of body weight loading on the right lower limb before and during the reaching movements were compared across target heights conditions.