It is a striking moment: ceremonial guards swinging open the Kremlin's golden doors to reveal Russian President Vladimir Putin striding down the red carpet for his 2012 inauguration.

But in the eyes of some, what truly makes the moment remarkable is not the lavishness of the ceremony, or the fact that it is Putin's third presidential term, but the way Putin's right arm lacks the swagger of the rest of his body, resting almost rigidly at his side.

Putin's prominent gait even led to speculation in a 2005 profile in The Atlantic that he had potentially suffered a stroke.

However, a new study may have cracked the mystery surrounding the world's most famous walking stride.

In the paper, neurologist and movement disorder enthusiast Bastiaan Bloem says that Putin, as well as several high-ranking Russian officials, have a "gunslinger's gait" that may have been "triggered by KGB or other forms of weaponry training."

After watching numerous YouTube videos of the Russian president, Bloem was struck by what he classified as a "consistently reduced right-sided arm swing."

Initially, the Dutch professor, who is an expert in Parkinson's disease, considered Putin's reduced arm swing to be an indication of an early phase of the nervous system disorder.

But in a search for other possible explanations, Bloem and his team came across a KGB training manual, which instructed operatives to restrict their body's movement to one side.

"When moving, it is absolutely necessary to keep your weapon against the chest, or in the right hand," says a quote from the manual in the study's press release.

"Moving forward should be done with one side, usually the left, turned somewhat in the direction of the movement."

After his graduation from university in 1975, Putin underwent a year of training with the KGB in Okta, Leningrad. In total, he spent 16 years serving with the security agency.

Bloem and his team pursued the theory further, and managed to identify several other high-ranking Russian officials who walk with the gunslinger's gait, including Prime Minister Dmitry Medvedev, former ministers of defence Anatoly Serdyukov and Sergei Ivanov, as well as Col. Gen. Anatoly Sidorov.

Ivanov spent 15 years in the KGB, where he became friends with Putin.

The researchers say that the more "plausible explanation," rather than interpreting the pattern as pathological, is that it is a habit that was picked up during weapons training, such as those provided by the KGB.

"We propose that this new gait pattern, which we term 'gunslinger's gait,' may result from a behavioural adaption, possibly triggered by the KGB or other forms of weaponry training, where trainees are taught to keep their right hand close to the chest while walking, allowing them to quickly draw a gun when faced with a foe," says the study.

The authors also found examples of "reduced arm swings" depicted in Wild West movies.

The findings were published in the medical journal BMJ on Monday.