title: The effect of height, weight and head circumference on gross motor development in achondroplasia.
abstract: OBJECTIVE
  This study aimed to investigate whether height, weight, head circumference and/or relationships between these factors are associated with gross motor milestone acquisition in children with achondroplasia.
  
  
  METHODS
  Population-based data regarding timing of major gross motor milestones up to 5 years were correlated with height, weight and head circumference at birth and 12 months in 48 children with achondroplasia born in Australia and New Zealand between 2000 and 2009.
  
  
  RESULTS
  Although as a group children with achondroplasia showed delayed gross motor skill acquisition, within group differences in height, weight or head circumference did not appear to influence timing of gross motor skills before 5 years. The exception was lie to sit transitioning, which appears likely to occur earlier if the child is taller and heavier at 12 months, and later if the child has significant head-to-body disproportion.
  
  
  CONCLUSIONS
  This is the first study to investigate the relationship between common musculoskeletal impairments associated with achondroplasia and timing of gross motor achievement. Identification of the musculoskeletal factors that exacerbate delays in transitioning from lying to sitting will assist clinicians to provide more proactive assessment, advice and intervention regarding motor skill acquisition for this population.
authors: Queensland Paediatric Rehabilitation Service, Royal Children's Hospital, Brisbane, Queensland, Australia. penny_ireland@health.qld.gov.au
authors: Penelope Jane
authors: PJ
authors: Ireland
authors: Robert S
authors: RS
authors: Ware
authors: Samantha
authors: S
authors: Donaghey
authors: James
authors: J
authors: McGill
authors: Andreas
authors: A
authors: Zankl
authors: Verity
authors: V
authors: Pacey
authors: Jenny
authors: J
authors: Ault
authors: Ravi
authors: R
authors: Savarirayan
authors: David
authors: D
authors: Sillence
authors: Elizabeth
authors: E
authors: Thompson
authors: Sharron
authors: S
authors: Townshend
authors: Leanne M
authors: LM
authors: Johnston
mesh_terms: D000130:Achondroplasia / Q000150:complications / Q000503:physiopathology*; D001315:Australia; D001827:Body Height / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D002508:Cephalometry; D002657:Child Development / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D019957:Motor Skills Disorders / Q000209:etiology / Q000503:physiopathology*; D009520:New Zealand