Thanks for posting your query.
There may be possibility of localized bruise
formation or hematoma
formation in neck muscle.
Presence of pain aggravating on neck movement suggests the diagnosis.
You should consult with general physician and should go for thorough check up.
You should also apply analgesic
ointment along with hot fomentation for speedy recovery.
You should also take muscle relaxants.
Dr. Mayank Bhargava