If there’s a way of walking that’s achieved a modicum of celebrity — discounting Monty Python’s “silly walk” — it’s the goose step, that chopping, stiff-legged march made infamous in World War II by Nazi soldiers tromping in untold numbers across treeless plazas. Legs mechanically up and down. Knees unbent. Toes pointed upward. Arms oscillating precisely. It’s a step that exists now primarily in that thorny borderland between absurdity and terror.

The step — the Prussians called it Paradeschritt or, later, Stechschritt — apparently took root with guards in the Holy Roman Empire, and then found its way to Prussia around 1730. It persisted until 1940, which was the last year the Nazis taught newly drafted soldiers how to goose step, instead shifting to more practical skills. (It was renamed the “Roman step” when Benito Mussolini brought it to Italy in 1938.)

In truth, it’s not a very sensible way to get around (goose-stepping injuries weren’t uncommon among soldiers), but it was taught to instill discipline among the troops. More so, it served well in ceremonial public displays — to demonstrate a leader could turn men into machines. The step invariably involved boots brought down in unison, smartly and loudly, giving a platoon the invincible sound of a well-lubricated machine. Message: Resistance is futile.

For the past century or so, the goose step has been used chiefly in totalitarian regimes — that is, states where it’s exceedingly inadvisable to laugh at the military. (George Orwell wrote in 1940, “Its ugliness is part of its essence, for what it is saying is ‘Yes, I am ugly, and you daren’t laugh at me.’”) Today, the goose step is about as commonly seen as the Hitler’s toothbrush mustache, although it does live on vestigially among some ceremonial guards (Greece’s parliament, Moscow’s Tomb of the Unknown Soldier) and in a faraway, possibly mythical, land called North Korea.

Meanwhile, across the border in France, the French military has also long been interested in teaching its infantry how to march, although with an eye less to the ceremonial and more to the practical. At the end of the 19th century, the French Army emerged as the leading proponent of the slouchy, somewhat slovenly “bent-knee” method of long-marching. The gait was modeled after infants learning to walk, with knees angled and the body pitching slightly forward. The idea was that, by leaning in the direction of travel, gravity would pull you along and make it easier to cover vast distances with less energy. In its way, the French army walk looked as silly and unnatural as the goose step.

The debate over walking styles spilled over into civilian circles in the early years of the last century, when long-distance walking enjoyed a brief mania. “The correct step may be learned in the drawing room,” instructed one 1903 British manual. “There is no difficulty about it. It may be tried now.” The book was comprehensively entitled, How to Walk, Describing the Whole Art of Training Without a Trainer. Full Instructions and Hints for Those who Intend Entering Walking Contests Either for Short Or Long Distances, and a Special Chapter on Walking for Women.

An article in the New York Times in 1908 pondered a walking question, asking “Is our method of walking correct or incorrect?” The story rehashed the debate over the straight-leg vs. bent-knee style. At the reporter’s request, a “famous wrestler” tried the bent-knee gait across the lobby of a hotel. He “was quite disgusted at the result,” it was reported.

Still, the Times writer himself was well-disposed toward the French Army style, noting that “they hold all sorts of record for long-distance marching.” But he warned readers to use it only in the proper context. “No man who walks less than three miles a day need worry about bending his knees,” he wrote, adding, “it would not do in cities. It is against all our aesthetic and social principals. Why, if a man went about New York with bent knees he would look like an ape.”

Americans don’t often stray into in-depth discussions of walking these days, except in the context of how to avoid it, just as we don’t talk about spatterdashes or the many uses of borax. That’s not to say we’ve lost the vocabulary: there’s shamble, shuffle, stroll, tramp, tromp, slog, saunter, amble, trudge, plod, dawdle, march, stride, traipse, and mosey. But they tend to exist now in a sort of vocabulary ghetto, employed chiefly by hard-up novelists looking for a shortcut to describe two things at once: mood and mobility. (“Marching toward Bethlehem” is a much different proposition than “slouching toward Bethlehem.”)

Since society abandoned walking en mass for riding in upholstered comfort atop a metal box harnessed to a series of small explosions, we hardly pay attention to how we walk. But others do, and we may be coming full circle, after a fashion. Governments are again are showing interest in how its citizenry walks — not in prescribing the proper method, but as a form of identification.

Our natural gait, it turns out, defines us as humans. Not speaking broadly — that we’re only truly bipedal mammal on the earth, blah blah blah — but as individuals. Researchers are increasingly convinced that how we walk can identify us as unique individuals, much like a fingerprint or retina scan.

This sort of research has been underway since the late 1990s, picking up more urgency after the 2001 terrorist attacks on New York and Washington, and the London train attack in 2005. DARPA and Homeland Security, among others, are keenly interested in video analysis programs that can separate out and analyze an individual gait, then use this like fingerprints. DARPA has been sponsoring “human identification at a distance” studies since 2000, which often combines gait analysis with facial and gesture analysis. It’s a hot field right now, and has been heralded as a less invasive approach than retina scans or blood tests or fingerprinting. One study I read on the algorithms of walking put the appeal simply: “Advantages include the fact that it does not require subject cooperation or body contact, and the sensor may be located remotely.”

The University of Southampton in England is among those in forefront of this research, and is home to the ECS Biometrics Tunnel. A subject walks through this short tunnel, and his or her gait is captured at various angles by twelve cameras. Software sifts out the noise, and reduces the walker to a handful of data points that then calculates a signature for each individual. The university has reported about 90 percent accuracy, and is working to improve that. Someday, it may be possible to use this technique as a filter to strain through the vast river of data flowing from the ever-expanding numbers of security cameras at stadiums and airports and city streets, and checking this against a database of known evildoers.

But I suppose there’s one way not to be identified: When you see the gait cameras, try goose-stepping past. Leg up high, knee unbent, toes skyward. It’s wholly unnatural and artificial, but should mask the way you really walk. No one will ever know it’s you. • 21 January 2013