Traditional biomechanical analysis and research have been extensively applied into the research of medical engineering. Due to the open-source of OpenSim modelling, it has developed rapidly and been widely utilized. This paper reviewed studies of image-based subject-specific OpenSim Musculoskeletal Modelling to lower extremity biomechanics between 1 Jan 2007 and 31 October 2018. Based the inclusion and exclusion criteria of literatures, tweenty full-paper English articles were obtained. Apart from the basic kinematic and kinetic data, subject-specific OpenSim model could reveal information of neuromuscular control, muscle forces and geometry, and contact forces. Image-based modelling of the neuromuscular control and ergonomic evaluation of prostheses confirmed the reliability and feasibility, but showed limitations in time-consumption and foot-ankle modelling. This reviewed presented subject-specific modelling of pathological gait could improve the accuracy and diversity of clinical biomechanics and medical engineering research. It could also reveal the pathological features, and provide scientific evidence to design specific and accurate protocols of motor function diagnosis and rehabilitation, health monitoring and evaluation, and ergonomic customization and assessment of devices. Future directions and implications were provided in the research field.