A method for an assessment of a movement of a limb-related point in a predetermined 3D space effected by a user displacing the limb in the 3D space is provided. The method includes the steps of providing display surfaces in the 3D space around the user, providing a limb position point connected to a portion of the users limb associated to the limb-related point, and providing sensors to detect the limb position point in the 3D space in relation to the joint. A computer program calculates a direction defined by a straight line between the joint and the limb-related point and provides a representation of the position of the limb-related point in the 3D space as a function of a distance between the joint and the limb-related point on one of the display surfaces on the line.
