Congenital muscular torticollis (CMT) is a postural, musculoskeletal deformity evident at, or shortly after, birth. It results from unilateral shortening and increased tone of the sternocleidomastoid (SCM) muscle and presents as lateral flexion of the head to the ipsilateral side with rotation to the contralateral side . It is potentially a painful condition for infants and can present with a pseudotumor in the SCM muscle . It is the third most common congenital musculoskeletal condition in newborns with an incidence ranging from 0.3 to 16% . CMT has been associated with dysfunction in the upper cervical spine and is sometimes referred to as kinetic imbalance due to subocciptal strain (KISS) . Treatment approaches for CMT include manual therapy (including practitioner-led stretching exercises) , repositioning therapy (including tummy time)  and, in severe non-resolving cases, botulinum and surgery . CMT can lead to secondary changes such as cranial asymmetry, and also to functional problems, including breastfeeding problems .
Cranial asymmetry, also known as plagiocephaly, is the most common form of ‘flat head syndrome’ and presents itself as an asymmetrical head shape. Positional plagiocephaly (PP) (sometimes referred to as deformational plagiocephaly or non-synostotic plagiocephaly) typically occurs in infants and results from mechanical factors which, when applied over a period of time in utero, at birth, or postnatally, alter the shape of the skull . In this condition there is flattening of one side of the occiput, with anterior displacement of the ipsilateral ear. The region of occipital flattening relates to the side that the head is toward when in the supine sleeping position .