Arms are how we reach, hold and defend, so tradition reads them as your capacity to act and to care for others. Strong arms speak of feeling capable; weak or tied ones of help you cannot give or receive.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.