Age-dependent differences in the gait of rats.

Middle-aged (16-17 month) and aged (29 resp. 31-33 month) female Sprague-Dawley rats were assessed for age-dependent changes in gait. Stride length and gait symmetry decreased significantly with age. Stance width distributions changed from normal to bimodal. Changes in stride length and stance width were even significantly different between 29 and 31 months of age. Their retest reliability was high for middle-aged and aged rats. All three parameters have a potential as markers of aging or disease for intra- and interindividual comparisons.