Vaseline Coating on Paw Soles Alters the Spontaneous Gait of Rats

Spontaneous walking behavior is modulated by various factors, but it remains almost unknown whether and how moisturizing paw soles of rats alters their gait. To this end, we allowed rats to spontaneously walk on a disk-shaped treadmill before and after their paw soles were coated with white petrolatum (vaseline) and monitored the rat's walking. Using DeepLabCut- and DeepEthogram-based pipelines offline, we calculated the shoulder-elbow-wrist angle and defined the distance as the trajectory of the wrist. The distance was shorter in the stance phase but longer in the swing phase after vaseline was treated than before. The duration of the stance and swing phases was shorter in the vaseline-treated period. The angle at forepaw landing and takeoff was smaller and larger, respectively, in the vaseline period. These findings underscore the dominance of moisturizing sole skins over the well-organized dynamics of a spontaneous gait.