Paw Step Cycle

Step-cycle is a single sequence of locomotion by one hindlimb from the reference paw contacts the ground until the same hindlimb contacts the ground on the next occasion \cite{perrot2009}. It composes of stance phase and swing phase. The definition of stance phase is the step cycle part which starts as soon as the foot touches the ground and terminates when the foot begins to move forward \cite{pereira2006}. This phase contains braking and propulsion phases. The braking phase is the time period between initial and maximal paw touches the ground. As the propulsion phase is the time interval between the stance phases and the beginning of the swing phase when the paw does not contact with the ground \cite{vincelette2007}. The definition of swing
Moving velocity in my research is the horizontal velocity along to the stepping trajectory. The speed (no vector information) is separated into 3 groups: slow speed, intermediate speed, and high speed. Slow speed is for walk gait which is defined by when only one hindlimb is in swing phase. Intermediate speed is for trot gait which is defined as the synchronous swinging of diagonal paws. Finally, the bound or gallop is used for high speed. A gallop occurs when only one paw is in the stance phase and no paws are in the stance phase or we called aerial phase \cite{mendes2015}. Step periodicity can be quantified by using Fast Fourier Transform (FFT) analysis applied to the horizontal component of the stepping trajectories \cite{fong2005}. The fundamental stepping frequency locates at the predominant peak. In the case of the poor stepping of the rat is shown, the fundamental peak is unclear because of a variety of the fundamental peak in the FFT spectrum. The full width at half maximum (FWHM) of the fundamental peak is the indicator for observing the stepping performance. The low value means that stepping is consistent and rhythmic. In contrast, a high value infers the consistent foot dragging and stumbling and the erratic