Head control and infant plagiocephaly: towards prevention

Abstract

The thesis investigated infant head control development for a new approach to prevention of deformational plagiocephaly associated with infants sleeping in supine (Back-to-Sleep) and reduced rates of Sudden Infant Death Syndrome (SIDS). Standard prevention advice is counter positioning and prone play or tummy time but has limited evidence. Reports of delayed development associated with plagiocephaly led to examination of infant head control as there had been no previous studies for this within a dynamical systems framework.

The objective was to explore infant plagiocephaly aetiology and prevention strategies in relation to head control development in infants and develop more effective prevention advice.

Mixed methods were used, including reviews, a survey of plagiocephaly awareness in community health professionals and an audit of specialist plagiocephaly clinics. Observational studies investigated the pull to sit test in three cohorts of infants: 1) infants with plagiocephaly; 2) 4-month-old infants; and 3) infants aged 1-4 months. A fact sheet for infants aged 2-8 weeks was developed and evaluated by an expert focus group.

Reviews confirmed that the aetiology unclear, but the environment was a factor and tummy time promotes only prone related motor skills. The survey of community Maternal Child Health (MCH) nurses (n=183) and paediatric physiotherapists (n=16) confirmed a gap in plagiocephaly prevention advice. MCH nurses’ primary strategy was referral, thus delaying intervention at a critical age. A 3-year audit of specialist plagiocephaly clinics (n=4000 reviews, n=1990 individuals) revealed delays in consultation. Infants with plagiocephaly, aged 7 SD2.5 months (n=24) showed that they had poor antigravity head control and adopted an extended posture in supine for the pull to sit. A cross-sectional study of normal infants aged 4-months (n=53) showed variation in pull to sit. Over half had poor chin tuck (51%), early head lag (66%) and extended posture (57%). (3) An investigation of head control development over time of infants in the community aged 1-4 months (n=32) including some with plagiocephaly (n=5), all achieved antigravity head flexion control with chin tuck and flexed posture for pull to sit by 3-4 months.

The variations observed in the ability of infants to flex their head and neck against gravity or engage associated arms, trunk and hip flexion posture for pull to sit enabled a new operational definition of head control. The 1 to 4-month normal group achieved head control with postural adjustments, chin tuck and flexion, due to the early experience and modelling by a physiotherapist. A new Baby’s Head Shape Fact Sheet: face time plus tummy time equals head control, approved by an expert focus group at the Royal Children’s Hospital (RCH), is to counter infants spending awake time in supine and not developing competent antigravity head control. It is designed for use by Maternal Child Health (MCH) Nurses and physiotherapists in for infants 2 to 8 weeks, the aim being to encourage parents to interact with their baby, encourage early volitional head rotation and development of antigravity neck strength for postural transitions. The implementation of the Baby’s Head Shape Fact Sheet forms a starting point for research to reduce rates of plagiocephaly.