The aim of this thesis is to move mobile gait analysis systems based on inertial sensing closer towards clinical grade wearable devices. Such devices are envisioned to be used in everyday clinical practice for objective gait assessment under supervised conditions as well as for remote monitoring of gait in real-life environments. Such applications, however, require clinical grade of the wearable device established through clearance by the authorities and this process needs to be based on scientific research. The present thesis moves towards this aim in three main areas: Benchmarking methodological choices in foot trajectory reconstruction, extending the stride parameterization with kinetic features and reducing the assumption set current mobile gait analysis systems are built upon in order to widen the scope of gait disorders these systems can be used in.