An exoskeleton (100) of the lower extremities, configurable to be coupled to a person (187), said exoskeleton comprising the lower extremities: two supports (101, 102) for the configurable legs to be coupled to the lower extremities of said person and configured to rest on the floor during its support phases next to the feet of said person, which rest on the floor, each of said leg supports comprising an articulated bar (103, 104) for the thigh and a bar articulated (105, 106) for the calf, and said two leg supports being arranged, during their support phases, to transfer forces from their calf bars to the ground； two knee joints (107, 108), each configured to allow flexion and extension between the respective calf bar and the respective thigh bar； and an exoskeletal trunk (109) configurable to be coupled to the upper part of said person's body, rotatably connectable to said thigh bars of said leg supports, allowing flexion and extension between said leg supports and said exoskeletal trunk； two torque generators (110, 111) coupled to said knee joints； and a motor group (201) capable of providing power, coupled to said torque generators, the motor group being configured to operate in at least two modes for each torque generator, said motor group including a power injection subcomponent (240) , capable of injecting power to the torque generator, and a power dissipation subcomponent (200), capable of dissipating power from the torque generator, in which: when said motor group operates in its first mode with respect to one of said generators of torque, said motor group injects power into one of said torque generators to extend a respective defined knee angle between the respective calf bar and the respective thigh bar, and when said motor group operates in its second mode with respect to to one of said torque generators, the energy required for said flexion and said extension between the respective calf bar and the respective thigh bar of said corresponding The leg supp
