Torticollis is a form of dystonia (prolonged muscle contractions) in which the neck muscles contract involuntarily causing the head to turn. 

Torticollis may occur without known cause (idiopathic), be genetic (inherited), or be acquired secondary to damage to the nervous system or muscles.  It may develop in childhood or adulthood.  Congenital torticollis (present at birth) may be caused by malpositioning of the head in the uterus, or be prenatal injury of the muscles or blood supply in the neck.