the.com/flatfoot

means An old slang term for a police officer, especially a beat cop who patrols on foot.

from American slang from the early 1900s, built plainly from 'flat' + 'foot' — the literal condition of fallen arches that came from hours spent walking a beat on hard pavement. The term carried a double edge: it named the cops' sore, flattened arches while also mocking the plodding, flat-footed gait of a patrolman making his rounds. It stuck as underworld and newspaper slang before settling into general use as a (mildly derisive) word for any policeman.