If someone has power of attorney over you does that mean you no longer have any right to make decisions...?

Can you no longer make any decisions for yourself?

My aunt and uncle are 70 and 71 years old and her oldest son has power of attorney over her. He will no longer allow her to live in the house she lives in with her husband because he feels that his brother (who lives in another city) and his family can take better care of her, so that's where she is. My uncle has also gone to stay at her son's house so that they can be together but they both want to leave. My uncle will stay with her at the son's house as long as she is forced to be there but they both want to go home.

My aunt had a stroke a few years ago but she can still walk, talk, feed herself and can communicate her needs perfectly, she just cannot be left alone because she is a bit unsteady.

By the way, her children are not trying to keep my aunt and uncle apart they just feel that he is unable to care for her on his own, which is true but they won't consider any other options.

They are forcing her against her will, is this legal because of the son's power of attorney?