An assistive lower-limb exoskeleton including a system for mitigating or correcting knee hyperextension in a user with the assistive lower-limb exoskeleton, the assistive lower-limb exoskeleton comprising: a wearable frame having trunk from which an actuation system for bilateral hip flexion/extension movement extends including actuation devices connecting to first and second hip joints having at least one sensor and linking to first and second leg units; wherein the system for mitigating or correcting knee hyperextension is arranged: (a) to identify a first hyperextension in a knee joint of a user's limb during a stance phase of a gait cycle; (b) to determine a first flexion assistance for an assistance profile based on the first hyperextension of a knee joint by: (i) determining a timing of the first flexion assistance; (ii) determining a duration of the first flexion assistance; and (iii) determining an amplitude of the first flexion assistance; (c) to apply an assistive flexion torque by the assistive lower-limb exoskeleton to a user's limb during the stance phase according to the first flexion assistance of the assistance profile; wherein the assistive lower-limb exoskeleton includes a power unit and a controller, the power unit is arranged to provide assistive power to the actuation devices for driving a transmission unit of the first and second leg units at the first and second hip joints based on the assistance profile determined by the controller based on input signals provided by the at least one sensor; wherein the at least one sensor is arranged to determine at least one gait parameter; wherein the controller is arranged to determine the amplitude, the duration and the timing based on the at least one gait parameter; wherein the controller is arranged to actuate the actuation system at least during a stance phase, at an amplitude, a duration and a timing based on a knee hyperextension of the at least one limb. a wearable frame having trunk from which an actuation system for bilateral hip flexion/extension movement extends including actuation devices connecting to first and second hip joints having at least one sensor and linking to first and second leg units; wherein the system for mitigating or correcting knee hyperextension is arranged: (a) to identify a first hyperextension in a knee joint of a user's limb during a stance phase of a gait cycle; (b) to determine a first flexion assistance for an assistance profile based on the first hyperextension of a knee joint by: (i) determining a timing of the first flexion assistance; (ii) determining a duration of the first flexion assistance; and (iii) determining an amplitude of the first flexion assistance; (c) to apply an assistive flexion torque by the assistive lower-limb exoskeleton to a user's limb during the stance phase according to the first flexion assistance of the assistance profile; (a) to identify a first hyperextension in a knee joint of a user's limb during a stance phase of a gait cycle; (b) to determine a first flexion assistance for an assistance profile based on the first hyperextension of a knee joint by: (i) determining a timing of the first flexion assistance; (ii) determining a duration of the first flexion assistance; and (iii) determining an amplitude of the first flexion assistance; (i) determining a timing of the first flexion assistance; (ii) determining a duration of the first flexion assistance; and (iii) determining an amplitude of the first flexion assistance; (c) to apply an assistive flexion torque by the assistive lower-limb exoskeleton to a user's limb during the stance phase according to the first flexion assistance of the assistance profile; wherein the assistive lower-limb exoskeleton includes a power unit and a controller, the power unit is arranged to provide assistive power to the actuation devices for driving a transmission unit of the first and second leg units at the first and second hip joints based on the assistance profile determined by the controller based on input signals provided by the at least one sensor; wherein the at least one sensor is arranged to determine at least one gait parameter; wherein the controller is arranged to determine the amplitude, the duration and the timing based on the at least one gait parameter; wherein the controller is arranged to actuate the actuation system at least during a stance phase, at an amplitude, a duration and a timing based on a knee hyperextension of the at least one limb.