This is a muscular spasm which temporarily causes an altered position of the head and neck. The head may be held to one side or in a twisted position. Sometimes the head may be held in a more forward position than usual.
Whiplash is a common injury that is caused by rapid acceleration and deceleration of the head and neck. Most injuries involve sprain and strain to the soft tissues (muscles and ligaments). Higher impact whiplash injuries can lead to bony injuries and nerve irritation which may cause pins and needles in your arm.