Torticollis is frequently caused by tightness of the sternocleidomastoid (SCM) neck muscle.

Babies with torticollis typically present with a postural preference of tilting the head towards one side and/or turning the head towards one side. In addition, some babies may also present with trunk postural asymmetry, evidenced by a propensity for the body to curve towards one side.

Notice the different head posture preferences below:

"Before and After" pictures of babies who have been treated by
EARLYstart Pediatric Physical Therapy: