There are a number of different causes of toe walking in children and they all need to be investigated by a pediatric health professional to identify the reason as a number of neurological conditions can cause it. The most common cause of toe walking in children is what is called idiopathic toe walking, in which there is no identifiable cause. This idiopathic toe walking is the most common type of toe walking in children.
The rigid carbon fiber plates that are only 1,2-1.5 millimeters thick have been shown in research to help improve the gait of those with idiopathic toe walking. They make the shoe more rigid across the ball of the foot (metatarsophalangeal joint), increasing the lever arm to the ankle joint to induce a subtle force to get the heel down to the ground.
The CarbonEAZE carbon fiber plates now come in the kids’ sizes (7 sizes from the small 150mm to the 210mm one). Like the adult sizes, they are sold as single, so you probably need to buy 2 to make a pair for idiopathic toe walking. These smaller kids’ sizes are only available in the full-width version and not the Morton’s extension version.
Measure the length of the insole in the shoe of the child and order that length. Going 5 or so mm shorter is usually not a problem.
For the latest on this, check this thread on Idiopathic Toe Walking at Podiatry Arena.