Hyper-extended knees (aka ostrich legs)

OP, never even knew that this was a thing?!?! Learned something new today, thanks to you.

It’s called Genu Recurvatum, and its etiology is usually present when a child is born, and developed in utero. Probable genetic trait? Not sure.

Lax muscles, incorrect pelvic alignment, and other causes. Don’t know them. Too lazy to read it all on Wiki.

Trauma, such as a car accident, fall, etc., can also cause the condition to present.

So whoever you see that has this? They cannot help it, and they need professional, medically licensed prisons, and specialized treatment, in order to correct it. It varies in severity.

Personally, I have never even noticed this as a irregularity.

in the dance world patois, it's considered banana leg

There was a girl I knew growing up in the 80s who had this. She had sloping shoulders, a pigeon breast and frizzy red hair and looked like Alice Kramden. She was also a terrible goody-two-shoes and super duper nice.

I haven’t seen it lately at all. Huh.

I’ve seen it, but never to the point where it looked like a deformity. I thought it was normal, and just a trait of people who are more flexible?

I don’t think it looks bad. If it’s too hyperextended, then there will definitely be posture issues that will be really obvious.

It should be corrected, at any rate, because it will eventually cause problems as the person ages, according to some stuff I quickly glanced over, online.

I dated a guy with this--a Puerto Rican with a nice body. I always wondered why he didn't consciously slightly bend them to compensate, but maybe it would be uncomfortable to do so.

One friend who had only seen him in pants asked me if he had prosthetic legs.

My elbows do this. Luckily I don't stand on my arms. I always forget about it until someone points it out to me, which is rare.

On behalf of all the rarities I can say we don't find it amusing nor appropriate to be associate with that disgusting picture of those overly hirsute legs

Former dancer, here. Never heard "banana legs. That term must come from some horrible tap and baton twirling Academy in Oklahoma. Always "sabre legs."

Our bodies have an infinite number of variations, large and small. This is just one of them. Most people with sabre legs would not even know, unless they took ballet class.