PEDIATRICS Vol. 108 No. 5 November 2001, p. e84
Received Mar 23, 2001; accepted Jun 25, 2001.

From the * Division of Kinesiology, University of Michigan, Ann
Arbor, Michigan; and the Objective. On average, infants with
Down syndrome (DS) learn to walk about 1 year later than nondisabled
(ND) infants. The purpose of this study was to determine if practice
stepping on a motorized treadmill could help reduce the delay in
walking onset normally experienced by these infants.
Methods. Thirty families of infants with DS were randomly
assigned to the intervention or control group. All infants were
karyotyped trisomy 21 and began participation in the study when they
could sit alone for 30 seconds (Bayley Scales of Infant
Development, Second Edition 1993, item 34). Infants received
traditional physical therapy at least every other week. In addition,
intervention infants received practice stepping on a small, motorized
treadmill, 5 days per week, for 8 minutes a day, in their own homes.
Parents were trained to support their infants on these specially
engineered miniature treadmills. Every 2 weeks research staff went into
the homes and tested infants' overall motor progress by administering the Bayley Scales of Infant Development, Second
Edition,1 monitored growth status via a battery of
11 anthropometric measures, and checked parents' compliance with
physical therapy and treadmill intervention. The primary measures of
the intervention's effectiveness were comparisons between the groups
on the length of time elapsed between sitting for 30 seconds (entry
into the study) and 1) raising self to stand; 2) walking with help; and
3) walking independently.
Results. The experimental group learned to walk with help
and to walk independently significantly faster (73.8 days and 101 days,
respectively) than the control group, both of which also produced large
effect size statistics for the group differences. The groups were not statistically different for rate of learning to raise self to stand but
there was a moderate effect size statistic suggesting that the groups
were meaningfully different in favor of the experimental group.
Conclusions. These results provide evidence that, with
training and support, parents can use these treadmills in their homes
to help their infants with DS learn to walk earlier than they normally
would. Current research is aimed at 1) improving the protocol to
maximize outcome; 2) determining the impact of treadmill practice on
walking gait patterns; 3) testing the application to other populations with a history of delays in walking; and 4) determining the long-term benefits that may accrue from this form of activity.
motor development, Down syndrome, early intervention, walking.
Department of Exercise and Sport Science,
Oregon State University, Corvallis, Oregon.