Specific Motor Disabilities in Downs Syndrome

SUMMARY Children with Down's syndrome (Mongolism) were compared with severely subnormal autistic children and with normal children on two simple motor tasks: pursuit rotor tracking and finger tapping. Although the groups were matched on initial tracking performance, Down's syndrome children failed to show any improvement after a 5 min rest, while both comparison groups showed a very marked improvement. Furthermore, in the finger tapping task, Down's syndrome children were abnormally slow compared to the other groups. Neither the level of mental development nor the degree of general mental retardation can account for these deficits. It is hypothesised that Down's syndrome is associated with specific difficulties in using long term motor programmes and that mongol children may therefore be dependent on simple feedback processes to perform motor tasks.