Katie now walks everywhere, although still with a scissor gait.

Scissor gait is a form of gait abnormality primarily associated with spastic cerebral palsy.

The main difference between spastic diplegia and a normal gait pattern is its signature "scissor gait" - a style that some able-bodied people might tend to confuse with the effects of drunkenness, multiple sclerosis, or another nerve disease.

Cleese, throughout the sketch, walks in a variety of silly ways (including one that briefly imitates the scissor gait of spastic diplegia), and it is these various silly walks, more than the dialogue, that has earned the sketch its popularity.

As there are many features of the Upper Motor Neuron Syndrome, there are likely to be multiple other changes in affected musculature and surrounding bones, such as progressive misalignments of bone structure around the spastic muscles (leading for example to the scissor gait in spastic diplegia.