I once took a class on tracking. When the instructor discussed gaits, he said when an animal is being aggressive, its gait will change and it will swing the legs on each side of the body together, instead of alternating normally.
He said it's true of humans too. If someone walks toward you the way these artists depicted, he's ready to fight. If he's mouthing off but walking normally, you're probably safe.
I have no scientific references to back any of this up so take it for what it's worth. The instructor was someone who tracks down a lot of lost people and fugitives for law enforcement, along with teaching survival classes.
(And this was walking, not running. He didn't claim anyone would run this way.)
I imagine the situation is slightly different for a quadruped gait than for a biped like us... but even walking like this looks profoundly weird if you see it in real life.
If someone glared at me across a rowdy bar, then walked towards me with a matched arm/leg gait, I would be rather more likely to burst out laughing than feel threatened.
I personally have no trouble noticing when this is wrong in drawings -- recently I saw that the RyanAir instructions on how to exit an aircraft get this wrong in a few places! -- but that's perhaps because when I was a child my siblings and I actually talked about this problem. E.g., if my little sister made this error in a drawing, my brother or I would point it out (not too unkindly, I hope) and demonstrate exactly what it looks like in real life to walk/run that way. I also remember just breaking into this kind of matched run spontaneously just to get a laugh. People who have never seen it before recognize instantly that something is dreadfully wrong, but it can take them a moment to figure out what's awry.
It's honestly hilarious to watch someone run this way -- I highly recommend trying it for entertainment purposes.
There's one exceptional circumstance when this is the natural gait: if you have a child sitting on each of your feet, and you are walking while dragging them along. THEN you need the extra lurch to help you keep moving.
The instructor demonstrated. It actually looked pretty intimidating. I guess whether it's laughable or scary depends on other aspects of the person's stance.
It's not so much walking across the entire bar, as taking the last few steps leading up to hitting you.
There are names for these different gaits in horses[1]. The difference between the natural and unnatural running motions seems to be exactly equivalent to the difference between a trot and a pace.
A side-angled fighting stance presents less of a target to your opponent and puts both limbs on that side in position to shield the torso and head from blows.
He said it's true of humans too. If someone walks toward you the way these artists depicted, he's ready to fight. If he's mouthing off but walking normally, you're probably safe.
I have no scientific references to back any of this up so take it for what it's worth. The instructor was someone who tracks down a lot of lost people and fugitives for law enforcement, along with teaching survival classes.
(And this was walking, not running. He didn't claim anyone would run this way.)