The invention relates to an ankle-foot orthosis which comprises means that limit the plantar flexion of the foot and which is configured to provide support for a user's foot drop. The ankle-foot orthosis comprises a lower leg shell comprising a foot support (3) and a lower leg support (7), as well as heel fixing means which position and/or fix a user's heel in the lower leg support. The plantar flexion motion of the foot is limited by the complementary action of the elastic (23) and the non-elastic (25) plantar flexion limiting means. The plantar flexion limiting means further lead to a dynamic return of the foot to an angle substantially equal to the angle value a2.
