The detection of differences in locomotor function is an important tool for the assessment of the severity of many conditions that affect the central nervous system (CNS), peripheral nervous system (PNS) and skeletal structures or muscles. CatWalk™ XT, our gait analysis system, provides automatic and sensitive detection of a full range of parameters related to footprints and the dynamics of gait.
Traditionally, methods such as BBB scoring, running wheels, and ink on paper are used. However, these are not always objective and quick to master, nor do they assess the temporal dynamics of gate accurately. The CatWalk XT method is both accurate and objective, and allows for a more detailed assessment of each individual footfall. CatWalk XT has proven itself as an objective, non-intrusive, and accurate tool for researchers in the field of spinal cord injury, Parkinson disease, arthritis, cerebral ataxia, and neuropathic pain.
Crossing the walkway
CatWalk XT is a system based on the voluntary movement of a rodent in an enclosed walkway. In practice, rats or mice can be pre-trained on the walkway to habituate and learn to cross the walkway without hesitation. Generally, a rat or mouse is regarded to be well-trained when it is able to cross the walkway from one side to the other, two times in a row, without interruption. During the experiment, the crossing of the animal through the walkway is captured from below by a high speed video camera. The video image is sent to a computer running the CatWalk XT software.
Illuminated footprints technology
The software automatically detects each part of the animal that makes contact with the floor. These are typically the four paws but can also be the animal’s tail or abdomen. The Illuminated Footprints™ technology allows for an accurate distinction between the parts of the animal that make contact with the floor, and parts that do not. The Illuminated Footprints technology even allows for assessment of how the animal’s body weight is distributed across the paws during locomotion. This is visualized in a 3D graph, giving you an immediate feel for the dimensions and intensity of each footfall.
During footprint classification, each footfall needs to be assigned to the correct paw. Visibility of the body contour facilitates easy manual classification. However, the Automatic Footprint Classification™ Module eliminates the need to classify each footprint manually. At the push of a button, all the footprints in a run are automatically classified.
High quality data
Using voluntarily walking animals helps to elicit a natural gait and prevents the gait adaptations introduced by the forced nature of a treadmill system. The drawback of using a natural gait is that there can be variability between the walking speeds of animals or the experimental groups they belong to. Because walking speed has an effect on various gait parameters, the CatWalk XT software allows you to filter all your runs so they become more homogeneous. This means it will select parts or runs that adhere to the criteria you have chosen. You can fine-tune this selection after classification and store the settings within the Data Segmentation Profile.
To translate your data into results, CatWalk XT offers a wide range of parameters related to individual footprints, the relative positions of footprints, the time-based relationship between footprints, toe spread, and paw angle. Based on these, indices such as the Sciatic Functional Index (to assess recovery in sciatic nerve functioning) and the index for interlimb coordination can be calculated. All results are presented as numerical outputs and can be exported to PDF, CSV, and XLS format for further analysis.