Effect of Treadmill Training and Supramalleolar Orthotsis Use on Motor Skill Development in Infants With Down Syndrome; a Randomized Clinical Study

Physical Therapy, March 2010; 90:382-390.
Julia Looper, ,Dale A.Ulrich

Summary by Jennifer Rosen, PT

This research article was very pertinent due to the fact that most of the children on my caseload wear some sort of orthotic, and there has been a lot of discussion between therapists about when to start using orthotics with our children presenting with low tone. Many of these children are delayed in attaining gross motor skills like sitting and walking by at least 6-12 months. There have been studies done showing that using orthotics improved balance and gait, and this is when many therapists begin to recommend them. This group of researchers wanted to look at the use of orthotics prior to walking. There have been studies done with children and how they attained the goal of walking. When they practiced supported stepping they started walking independently sooner than without this practice. These researchers decided to see if independent walking would begin sooner if they used the orthotics along with the supported stepping prior to independent ambulation. They randomly split study volunteers, all with Down Syndrome, into a control and an experimental group. The study began for each child when he or she was able to pull themselves to stand independently. The kids were evaluated using the Gross Motor Functional Measure (GMFM) at the beginning and end of the study. The kids in the experimental group were fitted with SureStep SMOs immediately and wore them 8 hours a day 5 days a week for the duration of the experiment. The families in both groups were given a small home use treadmill and were taught how to support their child when practicing. The kids used the treadmills for 8 minutes a day at a speed of .2, 5 days a week. They children in both groups used the treadmills until they could take 3 independent steps off the treadmill. The kids in the control group were then fitted for SMOs and used them 5 days a week for 8 hours a day. One month after the child took 3 steps independently, both the child was re-tested using the GMFM but without SMOs.

The experimental group began walking before the control group but statistically it was not found significant, partially due to the small sample size. Though overall GMFM improved for both groups, the control group improved more in the standing scale and the walking, running, and jumping scale. When plotted on a graph, the experimental group showed a linear improvement in the crawling and kneeling, the standing, and the walking, running, and jumping scales while the control group seemed to plateau.

The authors feel that SMOs may positively affect the rate attaining independent walking but may be detrimental to other gross motor skills. They suggest not using SMOs until the children with Down Syndrome are independently walking.

When looking at this study I have a few concerns. They were practicing ambulation but used the GMFM to assess a gain in skills, which looks at overall motor skills. I am concerned that it is not sensitive enough in ambulation and gait to show a gain in that skill. I also would like to know quality of gait with and without the use of SMOs. Both groups learned to walk, but by using SMOs, many kids improve their gait pattern by having a heel strike and push off. Those kids also have a neutral foot position in standing helping their knees and hips to develop more appropriately. The children that do not use orthotics have forces through their body that are not normal causing pronated feet which goes up the chain causing malformation of the knees and hips and abnormal pull of the muscles and ligaments in the joints. I also was concerned that the researchers had the experimental group wear SMOs a large amount of time a week for many months, though when testing their gross motor skills, they tested without the SMOs. As we know, the SMOs provide stability that the kids learn to rely on. If they had more time to practice without the SMOs, or if they tested with the SMOS on, the children may have done better. The children cannot be expected to do as well without the SMOs.