Development and consistency of gait in the mouse.

Mouse models of human disease may display developmental abnormalities or adult onset of the condition. Since many diseases are accompanied by gait disturbances, knowledge of normal gait development in the mouse and its adult characteristics might be valuable as standards against which to appraise disease progression and the efficacy of putative therapies. Assessment of the gait of mice from postnatal day (pnd) 13 to postnatal week (pnw) 80 was undertaken utilising video techniques to examine velocity, stride, stance and swing times and between pnw 29 and 80 using load cells for analysis of the vertical reaction force (P(z)) associated with limb placements. Some adult features are apparent by pnd 13, but in the hindlimb (HL) particularly, the adult pattern of relationships between stride, stance and swing are not established. Adult characteristics of forelimb (FL) deployment develop earlier than those of HL while the systems controlling HL stance develop earlier than those regulating its swing. All the features measured, however, such as the shorter stance and longer swing of FL compared to HL, are established in their adult form by pnd 24 and maintained throughout adult life. In healthy mice at pnw 80, there was no deviation from the adult pattern of gait in which P(z) transmitted via FL exceeds that via HL by around 5%. We did not detect any significant change in any other variable or in their relationships.