A congenital form of torticollis resulting from shortening of the sternocleidomastoid muscle and leading to a limited range of motion in both rotation and lateral bending.
Comment:
Congenital muscular torticollis is thought to result from injury to the sternocleidomastoid muscle during birth trauma, resulting in fibrosis and unilateral shortening of the sternocleidomastoid muscle. Congenital muscular torticollis is thus etiologically and phenotypically distinct from spasmodic torticollis.