UNRESTRAINED WALKING IN CATS WITH PARTIAL SPINAL LESIONS

In four cats with partial spinal lesions, performed at a low thoracic level, involving ventral quadrants and, to a different extent, the dor solateral funiculi, several parameters of locomotion were analyzed dur ing unrestrained walking at moderate speed (0.3-1.0 m/s). Special atte ntion was paid to the analysis of support patterns and the durations o f support phases in step cycles. The operated subjects displayed a muc h greater variability of support patterns than intact cats as well as changes in the relative duration of some support phases. The most stri king difference was an increase in the relative duration of support on two homolateral limbs accompanied by a reduction of support on diagon al limbs. These changes were mainly due to an impairment of fore-hindl imb coordination as shown by an increase in the phase shifts between t he movements of diagonal limbs. Other parameters of locomotion were es sentially unaltered, except for cats in which the lesion destroyed bil aterally major portions of the dorsolateral funiculi.