Ankle sprain is one of the most common injuries in sports with a majority of 85% are lateral ankle ligamentous sprain. The injury mechanism was suggested to be supination or a combination of inversion and plantarflexion. Recent quantitative studies revealed that plantarflexion might absent from a lateral sprain. Hence, the mechanism is still controversial and yet to be understood.

Computational modelling is an effective approach to predict soft tissue behaviours around the ankle in responding to injurious motions, and the effectiveness of the intelligent anti-sprain system. This information is difficult and even impossible to be measured experimentally on living humans. This thesis has three major objectives. The first objective is to develop a subject-specific computational rigid-body model of the ankle joint. The bone geometry is obtained by computer tomography of a real subject's lower limbs. Spring elements were added to the model in representing the ligaments. Experimental ligament stiffness of various physiological motions of ankle were obtained using three cadaveric ankle specimens being used for model validation. The second objective is to further understand the ankle ligamentous sprain injury mechanisms by simulating the subject-specific model. The model was driven by the temporal injury kinematics in gaining knowledge of the grade I lateral ankle sprain injury happened in our laboratory. Joint torque and ligament stiffness were estimated in causing this injury. The third objective is to evaluate the effectiveness of the intelligent anti-sprain system in restricting the rapid inversion motion and inversion velocity of the ankle joint. In addition to the temporal injury kinematics simulation, an eversion torque was added to the ankle model to represent the corrective eversion motion. The thesis highlighted the importance of incorporating subject-specificity in the computational model to study injury biomechanics, and to evaluate the patented intelligent anti-sprain system. Methodologies used in this thesis are not limited in understanding the ankle inversion ligamentous sprain injury mechanism but could be an aid to study other musculoskeletal injuries and as a guide in developing subjectspecific injury preventive devices and designing rehabilitation training programme.