Delays in Motor Development in Children with Down Syndrome

Children with Down syndrome (DS) present with delays in motor development. The reduced size of the cerebrum, brain maturation disorders, and pathophysiological processes lead to motor development delay. The aim of this study was to examine the gross motor function and estimate what motor abilities are significantly delayed in children with Down syndrome even if they attend physical therapy sessions. Another purpose of the study was to assess the functional balance.

The study group consisted of 79 children with DS (42 boys, 37 girls), average age 6 years and 3 months ± 4 years and 6 months. Participants were divided into 3 groups according to (i) age: <3 years old, 3-6 years old, and >6 years old; and (ii) motor impairment scale: mild (SNR 1), moderate (SNR 2), and severe (SNR 3). Children were assessed using the Gross Motor Function Measure-88 (GMFM-88) and Pediatric Balance Scale (PBS).

None of the assessed children developed all the functions included in GMFM-88. The standing position was achieved at the specified age by 10% of children in the first age group (<3 years old) and 95% of children aged 3-6 years. Similarly, the walking ability was performed by 10% of children under 3 years old and by 95% of children aged 3-6 years. The median score of PBS was 50 points (min. 34 p. - max. 56 p.). There was a statistically significant correlation between PBS scores and GMFM-88 scores, r=0.7; p<0.0001, and between balance scores and GMFM - 88 E (walking, running, jumping) (r=0.64; p<0.0001).

Motor development, especially standing position and walking ability, is delayed in children with Down syndrome. Balance and motor functions are correlated with each other, so both aspects of development should be consider together in physical therapy of children with Down syndrome.