Certain aspects provide a method of generating a physical activity model, including: receiving, via a motion capture device, motion data corresponding to a plurality of key states associated with a physical activity sequence; for each respective key state in the plurality of key states: determining a plurality of joint positions associated with the respective key state; determining a plurality of body segment positions associated with the respective key state based on the plurality of joint positions; determining a plurality of inter-state differentiation variables for the respective key state; determining one or more state characteristic metrics for the respective key state; and determining a classifier for the respective key state based on the one or more state characteristic metrics; and defining a physical activity model based on the one or more state characteristic metrics and the classifier associated with each key state.