подвернуть его лодыжку

может быть осмысленный фрагмент увидим?

подвернуть его лодыжку

СВОЮ

свою

Ну почему же?
Теоретически, *вне контекста*, я могу вывернуть ВАМ руку - или же ЕМУ - или же лодыжку. Почему бы и нет?

Каков вопрос - таков и ответ.

Because you can twist someone’s FOOT, but twisting one’s ANKLE happens when you take a wrong step and your foot goes sideways under you.

https://books.google.com/ngrams/graph?content=I+twisted+%2A+ankle%2C+he+twisted+%2A+ankle%2C+she+twisted+%2A+ankle&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t2%3B%2CI%20twisted%20%2A%20ankle%3B%2Cc0%3B%2Cs0%3B%3BI%20twisted%20my%20ankle%3B%2Cc0%3B%3BI%20twisted%20an%20ankle%3B%2Cc0%3B.t2%3B%2Che%20twisted%20%2A%20ankle%3B%2Cc0%3B%2Cs0%3B%3Bhe%20twisted%20his%20ankle%3B%2Cc0%3B%3Bhe%20twisted%20an%20ankle%3B%2Cc0%3B.t2%3B%2Cshe%20twisted%20%2A%20ankle%3B%2Cc0%3B%2Cs0%3B%3Bshe%20twisted%20her%20ankle%3B%2Cc0%3B%3Bshe%20twisted%20an%20ankle%3B%2Cc0

I know. That's why I said теоретически. And why past tense?

How about
And TWIST his toe with your right hand while you twist his ankle with your left.
You proceed to bend and twist his ankle backward.
Trying to pick him up , did you twist his ankle ?
In the moment he was off balance, Paul took the opportunity to twist his ankle, hard. Stanford expelled a painful yelp and fell over backwards.
He blocked Nick's kick with a hand, tried to twist his ankle...
...
?

I stick to my guns - such questions don't deserve a *serious* answer.

The ankle is a joint. In all those cases, the correct form would be “twist his
foot.” How do you twist an ankle backwards? You twist the foot backwards because it’s flexible.

Well, good or bad, all this was from books written mainly by authors with English-sounding names. People do read books and ask questions here.

https://www.google.com/search?q=%22twist%20his%20ankle%22&tbm=bks&lr=lang_en
And I didn't go beyond the first page of results.

Well, who is right?!

Grumbler sticks like a limpet to his guns while Uly's trying to twist his foot...

Just like people say “I could care less,“ and it’s considered normal and acceptable and appears in books, people talk about twisting a joint instead of flexible appendage like the foot “and stick to their guns.” It’s a free world))

No.
Those who ask questions want to understand the meaning. Just saying that the wording is incorrect and correcting it regardless of the context can be unhelpful as it can change the meaning.

There IS no context — just a disjunctive phrase of sorts which HINTS at the only possible and most common interpretation, which is that someone twisted their (own) ankle. To go fishing for another interpretation, with an added layer of illogicality, just for the sake of being contrary and saying something… anything, is just incomprehensible and confusing.

the only possible and most common

I see some contradiction here

only possible (if we’re being logical and realize that the ankle is a joint and not a flexible appendage that can be twisted), and most common (=used most frequently and correctly in the sense of twisting one’s own ankle, although also and more rarely used in the incorrect sense of “twisting” someone else’s ankle)

Ankle is a flexible joint!

I see some contradiction here

Он имеет в виду, что это очевидно, с вероятностью 99%, что это будет СВОЯ лодыжка)

Uly, look:
ANKLE
the joint (= place where two bones are connected) between the foot and the leg, or the thin part of the leg just above the foot:

exactly, it’s a joint

or the thin part of the leg just above the foot