The effect of height, weight and head circumference on gross motor development in achondroplasia.

PURPOSE: 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. METHOD: 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.

Functional performance in young Australian children with achondroplasia.

AIM: The aim of this study was to determine population-specific developmental milestones for independence in self-care, mobility, and social cognitive skills in children with achondroplasia, the most common skeletal dysplasia. METHODS: Population-based recruitment from October 2008 to October 2010 identified 44 Australian children with achondroplasia aged 3 to 7 years. Consenting parents of 35 children (16 males, 19 females 14 aged 3y; 12 aged 5y; nine aged 7y) reported their child's self-care, mobility, and social cognition function using the Functional Independence Measure for Children (WeeFIM-II) at the ages of 3 (n=14), 5 (n=12), or 7 (n=9) years. Children were excluded from the study if they had an additional neurological or musculoskeletal condition. RESULTS: Functioning improved in children with achondroplasia between the ages of 3 and 5 years, but not subsequently. Milestones in the achondroplasia group were delayed across all ages and domains compared with normative reference data. Children with achondroplasia required greater caregiver assistance for self-care and mobility skills than typically developing children based on normative data. Social cognition appeared to be an area of relative strength. INTERPRETATION: Children up to 7 years of age with achondroplasia show delayed milestone acquisition and a greater need for caregiver assistance for all domains. As functional delays are likely to be related to common musculoskeletal impairments associated with achondroplasia, access to physiotherapists, occupational therapists, and speech and language pathologists skilled in achondroplasia management may assist children and families to become more independent, particularly around the time of starting school.

Developmental milestones in infants and young Australasian children with achondroplasia.

BACKGROUND: Achondroplasia, the most common form of chondrodysplasia (inherited skeletal dysplasia), is characterized by a significant delay in the development of communication and motor skills, particularly during the first 2 years. Although some information regarding timing of development for children with achondroplasia is available, no study has evaluated simultaneously the pattern of skill development across multiple key developmental areas. METHOD: This study used a retrospective questionnaire to quantify developmental data on milestone achievement. Twenty families of children with achondroplasia throughout Australia and New Zealand were asked to document age of acquisition for 41 gross motor, fine motor, and communication and feeding milestones. More than one half of the items assessed were milestones identified in the Australian State Government Personal Health Record Books. The results are compared with previously available information regarding development of motor skills by a cohort of American children with achondroplasia. RESULTS: Although the results support previously reported delays in gross motor and communication skill development, fine motor development does not seem to be as delayed as previously suggested. Information on development of self-feeding skills is presented for the first time and occurs later in this group than the typically developing population. We describe 2 distinctive and previously unreported methods of transitioning between static positions commonly used by children with achondroplasia. CONCLUSION: Delays were reported across gross motor and communication and feeding skills but were not observed during development of fine motor skills. Additional information is also offered regarding a variety of unusual movement strategies demonstrated by young children with achondroplasia.