les/tes for body part

Need to know the context for the phrases to comment specifically. In general terms, my understanding of choosing between definite or possessive articles with body parts etc is :

1. Use the definite article  when it is unambiguous whose body part etc is referred to - context is important.   

2. Use the definite article with reflexive verbs; these verbs make it clear whose body part etc is referred to

3. Don’t use the definite article if the body part etc is the subject of the verb - use possessive article 

4. There are optional use situations - for these there is guidance, but you need to develop “a feel” by reading and listening to lots of French !

Special cases when you use mon/ma/mes/etc with parts of the body (French Possessive Adjectives)