The lower extremity exoskeletons (LEE) are used as an assistive device for disabled people, rehabilitation for paraplegic, and power augmentation for military or industrial workers. In all the applications of LEE, the dynamic and static balance, prevention of falling, ensuring controller stability and smooth human-exoskeleton interaction are of critical importance for the safety of LEE users. Although numerous studies have been conducted on the balance and stability issues in LEEs, there is yet to be a systematic review that provides a holistic viewpoint and highlights the current research challenges. This paper reviews the advances in the inclusion of falling recognition, balance recovery and stability assurance strategies in the design and application of LEEs. The current status of research on LEEs is presented. It has been found that Zero Moment Point (ZMP), Centre of Mass (CoM) and Extrapolated Center of mass (XCoM) ideas are mostly used for balancing and prevention of falling. In addition, Lyapunov stability criteria are the dominant methods for controller stability confirmation and smooth human-exoskeleton interaction. The challenges and future trend of this domain of research are discussed. Researchers can use this review as a basis to further develop methods for ensuring the safety of LEE’s users.

下肢外骨骼（LEE）用作残疾人的辅助装置，截瘫的康复以及军事或工业工人的增能。在LEE的所有应用中，动态和静态平衡，防止跌倒，确保控制器的稳定性以及人与骨骼之间的平稳交互对LEE用户的安全至关重要。尽管已针对LEES中的平衡和稳定性问题进行了许多研究，但仍需进行系统的综述，以提供整体观点并突出当前的研究挑战。本文回顾了在LEES的设计和应用中将跌落识别，平衡恢复和稳定性保证策略包括在内的研究进展。介绍了LEES的研究现状。已经发现，零力矩点（ZMP），质心（CoM）和外推质心（XCoM）思想主要用于平衡和防止跌倒。此外，Lyapunov稳定性标准是控制者稳定性确认和人与骨骼之间平稳交互的主要方法。讨论了这一研究领域的挑战和未来趋势。研究人员可以以此为基础，进一步开发确保LEE用户安全的方法。