Pelvic axis-based gait analysis for ataxic mice

• Unlike the conventional method in which the nasal apex and base of the tail are used for mouse gait analysis, we have developed pelvic axis.
• Based on this axis, we have established pelvic axis-based gait analysis method.
• The scatter plots together with the limb angle analyses clearly show the differentiability of the mice groups with central nervous system degeneration and the healthy mice group.

BackgroundAlthough different gait analysis methods such as Walking Track Analysis exist, they cannot be used to demonstrate the physical condition of mice with specific gait disorder characteristic. Therefore, we developed a new method for the gait analysis of such mice to accurately assess hind limb angle based on the pelvic axis.New methodWe established and verified a gait analysis method capable of pelvic axis-based limb angle measurement by video-recording the gait of a control mice group (C57BL/6J(B6)) and three ataxic mice (ataxic B6-wob/t, Parkinson's disease model (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treated (MPTP)), and cerebellum hypoplasia (cytosine-β-d-arabinofuranoside treated)) from the ventral side.ResultsThe assessed hind limb angles of B6-wob/t and MPTP-treated mice were significantly wider than B6 mice (p < 0.01). Moreover, we could draw separating lines with slopes of minus one that could separate the data of each group in the scatter plot of the normalized hind limb step width and angle.Comparison with existing methodsWe found no significance when we applied the already existing nose–tail method for the analysis of the hind limb angles of B6 and B6-wob/t mice. In the nose–tail method, since the whole body axis of the trunk varies while the trunk of the mouse is laterally bent changing the hind limb angle, B6 and B6-wob/t mice could not be differentiated. However, the two mice groups could be differentiated by the pelvic axis-based gait analysis method.ConclusionThe pelvic axis-based gait analysis method is promising and valid for mice with gait disorder.