Overview
CatWalk is a test apparatus and measurement tool in one. CatWalk consists of a glass plate on which a mouse or rat traverses from one side of the glass plate to the other. Light enters the long edge of the glass plate which is completely internally reflected. Only at those areas where the animal makes contact with the glass plate (typically the animal’s paws) light is able to escape. A video camera positioned underneath the glass plate captures the illuminated footprints and sends these to a computer running the CatWalk software. 

 

 

 

The CatWalk software records the position, timing, pressure, and dimensions of each footfall, and facilitates the classification of footfalls. On basis of these measurements, graphical output is generated and numerous endpoints are calculated. These endpoints can then be exported to spreadsheet programs for statistical analysis. 

Benefits

• Dynamic assessment: Besides footprints, CatWalk provides a host of parameters related to the dynamic aspects of footfalls and gait. Examples include: step sequences, duration of brake and propulsion phase, support formulas, and phase lags.
• Paw weight distribution: Catwalk precisely detects whether a paw makes contact with the floor or not, and if so, how much pressure the paw exerts on the floor. An animal that experiences pain in one of its paws will likely avoid supporting its weight with this paw; hence less pressure will be measured.
• Non-invasive testing: The recording of footprints on video occurs while an animal voluntarily walks in a dark, tunnel-like environment.
• Detailed and retraceable data: A human observer is no match for CatWalk. The computerized processing of footprints on video results in highly detailed, reliable and retraceable data.  
• Support by Noldus

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Components
CatWalk is a turn-key system that consists of the following components:

• CatWalk software 7.0
• Walkway: glass plate, corridor, light source, and frame
• Video equipment
• Computer equipment

Analysis
A large number of endpoints can be calculated from the raw data extracted from video:

• Endpoints related to individual footprints: e.g. brake/propulsion, swing phase duration, intensity (i.e. paw weight distribution), and footprint dimensions.
• Endpoints related to position of footprints: e.g. stride length, base of support, and distance between ipsilateral paws.
• Endpoints related to time-based relationships between footprints: e.g. footfall patterns, regularity index, phase lags, and support formulas.
• Other endpoints: e.g. contact duration of abdomen and tail.