Occupant kinematics analyzes how the occupants moved within the confines of a vehicle during a collision. It requires an analysis of the collision dynamics and the physical evidence. Other useful information may include data from event data recorders (EDRs), seat belt evidence, witness marks, biomechanics, and medical records. Occupant kinematics can be used to evaluate low-speed collisions, crash worthiness, occupant ejections, injury mechanisms, and seat belt usage.