I fell and twisted my ankle.
The area around my ankle is a little swollen.
Usually written in kana; the kanji 踝 is rare and may not be widely recognized.
Kanji form is uncommon; learners will almost always encounter the kana spelling.
The origin is uncertain; it may be a compound of くる (possibly related to 繰る 'to wind' or 枢 'pivot') and 節 (ふし) 'joint', but this is speculative.