Posture apparatus for rehabilitating alterations of the locomotor system includes a rectangular-shaped platform offering housing to two portions and receive a subject user, each portion respectively including a base reversibly respectively fixed to its corresponding portion and adapted to respectively support a support matching the left foot and a support matching the right foot of the subject; a belt with elastic band adapted to be worn by the subject; at least one elastic cord for connecting the belt with support elements present on the apparatus; at least two telescopic rods adapted to fix at a predetermined height the support elements; the apparatus conferring to the anatomic structures involved in the exercise, and to the feet of the subject, a high number of degrees of freedom of movement, with the matching feet supports divided into two transverse portions which allow the foot to perform a natural helical movement.