Shawgi Younis, Norsinnira Zainul Azlan


To gain the maximum benefit from robot assisted rehabilitation therapy, participants should be actively engaged in the training session and this can be done though assist-as-needed (AAN) strategy. The assist-as-needed (AAN) control strategy gains wide popularity in the field of rehabilitation robotics in the recent years with numerous positive outcomes. The strategy encourages subjects’ active participation during physical exercise systematically by modulating robotic assistance in accordance to subjects’ movement ability while at the same time discourage the slacking behavior in motor control. For effective implementation, an accurate and consistent estimation of subjects’ functional movement or motor ability is crucial and has been a major limitation for current implementation. The existing gap between the current robotic approach and clinical practices is also another important concern that can lead to conflict in the near future. This paper provides a systematic overview of the assist-as-needed control strategies and estimation techniques found in the research literatures till date. An overview of specific clinical practices in functional motor assessment and estimation procedure that runs parallel to the robotic system counterpart is also designed to provide the significance and challenges in bridging the gap between robotic and clinical practices. This review concludes with major findings in the state of the art in AAN robotic therapy and outlines of procedures for clinical adoption. The further research is required to determine the effectiveness of clinical assessment procedure alongside with the robotic therapy that can address this need by providing a consistent and accurate estimation of subjects’ functional ability.


Assist-As-Needed (AAN), control strategies, functional ability (FA), Clinical assessment, upper limb rehabilitation.

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