Answer:
Nothing. It is just a dream, they don't mean anything. Don't worry. You're fine.
Another possibility:
The emphasis on "physically" suggests that the injury could be coming from within the dreamer's body. Dreams are directly effected by physical conditions, inflammation, hormonal imbalances and everything else within the physical body. This might be a nudge from the subconscious that the dreamer is due for a health checkup.