Are there cases where a possessive pronoun is omitted?

Are there cases where the possessive adjective is omitted in a sentence, or is it always used?

For example, in a sentence like "Susan was walking with her hands in her pockets", is it necessary to say "her hands", and "her pockets"? In Italian, we don't say whose hands, or whose pockets if not in a sentence like "Susan was walking with her hands in Michael's pockets".

I was wondering if the use of the possessive adjective is strictly necessary in cases like these.

To me, it feels a bit unusual to say ?"Susan was walking with hands in pockets", but "Susan was walking, hands in pockets." seems perfectly fine.

English speaking people drop possessive adjectives and other pronouns all the time in their speech, but are much less likely to do so when writing things down. For someone learning English, it is probably better to keep them in, as it reduces ambiguity.

But yes, English does have a huge trend of clarifying many statements which could be perfectly clear from the context. But it's not a rule which must always be followed.

Another example: "The matron was standing there, staring at me, hands on her hips." Could be written as "The matron was standing there, staring, hands on hips." Whose hips her hands are on, is very obvious. Who she is staring at would have to be garned from context (i.e. the prior sentences).

So no, the possessive adjective is not strictly necessary, but until you intuitively understand when and where they can be dropped while retaining meaning, it is probably better to keep using them. But by all means, experiment.

In English, we tend to really strongly favor attributing the possessor of body parts. (Why? It's hard to point to a real reason.) In any case, I find it interesting that there is a certain construction where we can often get around using the possessive for body parts.

We have the following pattern (preceding question mark = awkward at best):

John shook his head. / ? John shook the head.

I am having some pain in my eyes. / ? I am having some pain in the eyes.

I need to blow my nose. / ? I need to blow the nose.

But with the following construction, we don't need the possessive:

John whacked me on the head.

I looked him in the eyes.

She kissed her boyfriend on the nose.