UNRESTRAINED WALKING IN INTACT CATS

In five freely moving cats walking with speeds of 0,4-1.0 m/s several parameters of locomotion were investigated. Special attention was paid to the analysis of support patterns and the duration of support phase s. The animals used almost exclusively (in 88 to 99% of steps) the 3-2 -3-2-3-2-3-2 support pattern in which phases of support on three limbs alternated with phases of support on two limbs, homolateral and diago nal. The relative duration of support phases showed a tendency to decr ease with increased locomotor velocity, except for the supports on dia gonal limbs which slightly increased. The mean duration of the majorit y of support phases was similar and ranged between 12.2 and 14.5% of t he step cycle. Phases of support on both hind- and one forelimb were s omewhat (about 5%) shorter. It is concluded that the relative stabilit y of support patterns and of the duration of support phases during wal king observed in the present experiment may serve as a template for co mparing changes in the gait produced by various CNS lesions.