Biophysical bases for delayed and aberrant motor development in young children with achondroplasia.

Achondroplasia, the most common skeletal dysplasia, is characterized by delayed and aberrant motoric development in childhood. Delays and aberrancy are secondary to the anatomical differences inherent in people with achondroplasia. We present a photographic essay documenting biophysical differences, aberrant pre-orthograde movement strategies, and selected adaptive techniques. A parental questionnaire assessed the presence of, predominance, and ages at which various types of pre-orthograde locomotion were observed. Fine and gross motor skills were assessed contemporaneously by use of the Denver Developmental Screening Test in 93 children with achondroplasia and were found to be more delayed than previously reported. Physicians, therapists, early-childhood educators, and parents should recognize that aberrant does not mean maladaptive and that different development is not defective development.