Effect of Treadmill Training and Supramalleolar Orthosis Use on Motor Skill Development in Infants With Down Syndrome: A Randomized Clinical Trial

Background Children with Down syndrome (DS) often display delayed onset of independent walking. Treadmill training is an effective intervention that leads to an earlier walking onset. In addition, orthoses often are provided to infants with DS to increase stability and promote earlier independent walking. However, this early use of orthoses has not been scientifically verified in infants with DS. Objective The purpose of this study was to provide insight into the developmental outcomes of early orthosis use in combination with treadmill training in infants with DS compared with treadmill training alone. Design This study was a randomized controlled trial. Setting This study was conducted in participants’ homes and in the motor development laboratory. Participants and Intervention Seventeen infants with DS entered the study when they could pull themselves to a standing position. They were randomly assigned to either a control group (which received treadmill training) or an experimental group (which received treadmill training and orthoses). During monthly visits to the infants’ homes, 3 minutes of treadmill stepping was recorded and each child's motor development skills were tested. The treadmill training ended once the child took 3 independent steps. One month following walking onset, developmental tests were readministered. Measurements The Gross Motor Function Measure (GMFM) was used to test motor skill development. Results The average (SD) time in the study was 268 (88) days for the control group and 206 (109) days for the experimental group. All infants showed significantly increased GMFM scores over time. At 1 month of walking experience, the control group had higher GMFM scores than the experimental group, with higher standing and walking, running, and jumping subscale scores. Limitations Limitations of this study included a small sample of convenience, a statistical model that may have reduced validity at the tail end, and a lack of blinding in the GMFM scorer. Conclusions Orthoses may have a detrimental effect on overall gross motor skill development.