I filled in at the shop for the end of this afternoon and, glancing at one of several nice books of Edwardian and Victorian photography, was reminded of the strange story of the "Alexandra limp". In the 1860s Alexandra of Denmark (then the Princess of Wales, later Queen Consort of Edward VII) developed a knee problem from rheumatic fever following childbirth. For several years, ladies at court and in high society affected a similar limp. This kind of emulation wasn't uncommon in royal circles: Professor Christie Davies' article Have recent Tory leaders lost elections because they were bald? at the Social Affairs Unit blog mentions various courts that imitated the royal hairstyle. Even more strangely, when Louis XIV had an operation for an anal fistula, courtiers went around with their bottoms bandaged to show sympathy for his pain.
Creeping to royalty is one thing, but many such affectations seem to have had little reason but fashion. The forward-stooping Grecian Bend in women is well-known, if only because it gave rise to the term "the bends" for decompression sickness (the connection being that the stooping pained posture of 19th century caisson workers - "sandhogs" - resembled that fashion).
There are many lesser-known ones. The Roman Fall of the late 1860s (satirised in a music hall song) was a pseudo-military stance in men, with shoulders thrown back; it was especially popular in England, apparently borrowed from a compulsory stance required of French military officers (see Passing Passing English of the Victorian Era, James Redding Ware, E. P. Dutton & Co, 1909). The "kangaroo droop" (or kangaroo drop) in women, apparently a consequence of straight-front corsets, involved holding your hands and arms like those of a kangaroo (see A Dictionary of Slang and Colloquial English, John Stephen Farmer, E.P. Dutton & Co., 1921). Slang dictionaries of the time also mention the "Italian wriggle", though they don't explain this one.
Is there some reason for it all? Maybe. Posture gives a message. George Bush, for instance, has attracted attention for his "power walk", copied by Tony Blair, with its unnatural knuckles-forward stance that purportedly conveys some kind of alpha male status. Ultimately, postural fashions may come down to our chimpy side: see Primate Gestures May Be Clue to Human Language, which reports "In the chimpanzees, we have one group, just one group, where the chimpanzees hold hands together above their heads when they groom each other with the other hand," de Waal says. "It's a very strange posture. It was developed by one female named Georgia, and she introduced her family members to it, and now all the chimps in the group are doing it". It's not so different from limping because the Queen does.