A fitness/medical device assisting the movement of the lower limbs during the walking activity is substantially composed of brackets firmly connected to the shoes, a set of substantially rigid rods (7, 7A) connecting the brackets with articulation joints (6, 6A, 8, 8A, 9), elastic or inextensible cables for connecting the brackets, and at least one spring (5) acting between the rods and the connecting cables. The shape and joints of the various components of the kinematic mechanism allows accumulating the energy produced by one of the lower limbs when getting in contact with the ground, in order to give it back to the other lower limb when lifting from the ground, so producing a great reduction of the energy needed in the walking activity and at the same time promoting the acquisition of a correct posture.
