Quantitative Gait Analysis
Gait analysis can reveal and characterize problems with motor coordination and balance. In the Noldus Catwalk apparatus a subject is placed in a walkway with a plate glass floor and moves to the opposite end while video is recorded from below. Light refracts through the glass at points of contact with the subjects foot pads. Rodent foot pads are elastic so that more pressure applied to a foot increases the surface area in contact with the glass, refracting more light. Software designed for quantitative analysis gives data for stride length and pattern, pressure exerted by each paw and other dynamic measures indicative of abnormal locomotion.
Hamers FP, Koopmans GC, Joosten EA. CatWalk-assisted gait analysis in the assessment of spinal cord injury. J Neurotrauma. 2006 Mar-Apr; 23(3-4):537-48.
The Rotor-rod testing apparatus is designed to allow measurement of motor coordination, balance and motor learning. A computer controlled motor driven cylinder is mounted in a cabinet divided into separate stalls allowing up to four subjects to be run simultaneously. Mice are placed on the textured cylinder and must walk forward to avoid falling. Initial speed, rate of acceleration and top speed are determined by user input to the software. A session ends for a subject when time expires in the program or the mouse falls on to a padded surface, breaking a photo beam. Latency to fall and rpm at the time of falling are recorded.
McFadyen MP, Kusek G, Bolivar VJ, Flaherty L. Differences among eight inbred strains of mice in motor ability and motor learning on a rotorod. Genes, Brain and Behavior 2003 2: 214-219
Grip strength test
Testing grip strength in mice is an efficient, non-invasive method to evaluate motor function in models of CNS disorders. The mouse is positioned so that either its fore or hind limbs instinctively grip a wire bar connected to a digital force gauge. The mouse is gently pulled away horizontally from the bar and the maximal amount of force required for release is recorded. All four limbs may be tested together by substituting a wire grid for the bar.
Maurissen JP, Marable BR, Andrus AK, Stebbins KE. Factors affecting grip strength testing. Neurotoxicol Teratol. 2003 25(5):543-53.
Anderson KD, Abdul M, Steward O. Quantitative assessment of deficits and recovery of forelimb motor function after cervical spinal cord injury in mice. Exp Neurol. 2004 Nov;190(1):184-91.