Syntax

Syntactic actants

Actant 1: whose ankle it is
(a) Genitive
(b) Possessive
Правая щиколотка Маши распухла. Masha's right ankle is swollen.
Он смотрел на её щиколотки. He looked at her ankles.
NB When the word щиколотка functions as a subject and does not have a descriptive modifier, the construction щиколотка у + Genitive is often preferred to (a) and (b), above:
Правая щиколотка у Маши распухла. Masha's right ankle is swollen.

Restrictive modifiers

(a) adjectival modifier
(b) noun phrase: Adj + Genitive of нога
(c) prepositional phrase: на + Adj + Prepositional of нога
NB Note that (a) is more common than (b) or (c).
левая/правая щиколотка the left/right ankle
Правая щиколотка у Маши распухла. Masha's right ankle is swollen.
щиколотка левой/правой ноги the left/right ankle
щиколотка на левой/правой ноге the left/right ankle