Gait is a characteristic unique to every individual and it reflects the health status of an individual. Analysis of the parameters associated with movement can impart some knowledge regarding the gait characteristics of a person. Hence the knowledge of gait abnormalities can aid in assessment and treatment planning. Joint kinematics is one such measure which has clinical implications. The work done in this paper is an effort to study the existing technologies and to tap the potential of inertial sensors in estimating the range of motion (RoM) of the Knee and the Hip joints. This requires appropriate signal processing in order to extract the information with the help of an efficient Inertial Sensor Unit (ISU) with robust and easy to implement signal processing techniques at various stages.