The Diagnosis
In the end, it was discovered that both Alexis and Nathan were diagnosed with cerebral palsy. This is a condition that limits movement and coordination, and it is widespread in premature babies. Despite having difficulty walking without assistance, both children have otherwise developed generally along with the rest of their siblings.
Nathan and Alexis have relied on walkers for the majority of their lives. Their ability to move around would have been severely limited without them. Growing up, Nathan became determined to learn how to walk. By pushing himself on a daily basis, he has become far less dependent on his walker.