A robotic device for the movement of a user, said robotic device comprising: - an interface frame arranged to connect said robotic device to a lower limb or to a lower limb prosthesis, said interface frame being integral to an axis x; - a lower portion integral to an axis y; - a resilient element having a first end connected to said interface frame and a second end connected to said lower portion, said resilient element being arranged to deform as a function of an angular variation θ between said axis x and said axis y; - a switching device comprising a first element, connected to said interface frame, and a second element, connected to said lower portion, said first and second element (121,122) arranged to carry out a relative movement s as a function of said angular variation θ between said axis x and said axis y; said robotic device being configured in such a way that: - when said relative movement s is less than a predetermined threshold value s * and said angular variation θ increases, said robotic device is in a first configuration and said resilient element deforms storing elastic energy, said switching device being configured in such a way that in said first configuration said relative movement s can take place only in one direction of motion; said robotic device being characterized in that it is configured in such a way that: - when said relative movement s is equal to said predetermined threshold value s *, as consequence of the condition s = s * said robotic device passes in a second configuration and said resilient element instantly releases elastic energy creating an angular moment M el arranged to oppose the increasing of said angular variation θ. - an interface frame arranged to connect said robotic device to a lower limb or to a lower limb prosthesis, said interface frame being integral to an axis x; - a lower portion integral to an axis y; - a resilient element having a first end connected to said interface frame and a second end connected to said lower portion, said resilient element being arranged to deform as a function of an angular variation θ between said axis x and said axis y; - a switching device comprising a first element, connected to said interface frame, and a second element, connected to said lower portion, said first and second element (121,122) arranged to carry out a relative movement s as a function of said angular variation θ between said axis x and said axis y; said robotic device being configured in such a way that: - when said relative movement s is less than a predetermined threshold value s * and said angular variation θ increases, said robotic device is in a first configuration and said resilient element deforms storing elastic energy, said switching device being configured in such a way that in said first configuration said relative movement s can take place only in one direction of motion; said robotic device being characterized in that it is configured in such a way that: - when said relative movement s is equal to said predetermined threshold value s *, as consequence of the condition s = s * said robotic device passes in a second configuration and said resilient element instantly releases elastic energy creating an angular moment M el arranged to oppose the increasing of said angular variation θ. - when said relative movement s is less than a predetermined threshold value s * and said angular variation θ increases, said robotic device is in a first configuration and said resilient element deforms storing elastic energy, said switching device being configured in such a way that in said first configuration said relative movement s can take place only in one direction of motion; said robotic device being characterized in that it is configured in such a way that: - when said relative movement s is equal to said predetermined threshold value s *, as consequence of the condition s = s * said robotic device passes in a second configuration and said resilient element instantly releases elastic energy creating an angular moment M el arranged to oppose the increasing of said angular variation θ. - when said relative movement s is equal to said predetermined threshold value s *, as consequence of the condition s = s * said robotic device passes in a second configuration and said resilient element instantly releases elastic energy creating an angular moment M el arranged to oppose the increasing of said angular variation θ.