The basic routine movements for elderly people are not easily accessible due to the weak muscles and impaired nerves in their lower extremity. In the last few years, many robotic-based rehabilitation devices, like orthosis and exoskeletons, have been designed and developed by researchers to provide locomotion assistance to support gait behavior and to perform daily activities for elderly people. However, there is still a need for improvement in the design, actuation and control of these devices for making them cost-effective in the worldwide market. In this work, a systematic review is presented on available lower limb orthosis and exoskeleton devices, to date. The devices are broadly reviewed according to joint types, actuation modes and control strategies. Furthermore, tabular comparisons have also been presented with the types and applications of these devices. Finally, the needful improvements for realizing the efficacy of lower limb rehabilitation devices are discussed along with the development stage. This review will help the designers and researchers to develop an efficient robotic device for the rehabilitation of the lower limb.