Syntax

Syntactic actants

Actant 1: whose wrist it is
(a) Genitive
(b) Possessive
Запястья Маши были тонкие, хрупкие. Masha's wrists were thin and fragile.
Он обхватил её запястье. He grabbed her wrist.
NB When the word запястье functions as a subject and does not have a descriptive modifier, the construction запястье у + Genitive is often preferred to (a) and (b), above:
Запястья у Маши были тонкие, хрупкие. Masha's wrists were thin and fragile.

Restrictive modifiers

(a) adjectival modifier
(b) noun phrase: Adj + Genitive of рука
(c) prepositional phrase: на + Adj + Prepositional of рука
левое/правое запястье the left/right wrist
Левое запястье у Маши было забинтовано. Masha's left wrist was bandaged.
запястье левой руки the wrist on the left arm
запястье на левой руке the wrist on the left arm