Nerve fiber = multicellular, containing both an axon and surrounding myelin sheath. The axon comes from a single neuron, but the myelin sheath is made by a train of many myelinating Schwann cells. In the case of unmyelinated axons, the unmyelinated fiber shares each Schwann cell with several other unmyelinated axons.
Flat feet (pes planus) occur when a child has no arch in their foot. Because an arch does not form, the foot appears to turn to the outside. Children with out-toeing due to flatfeet will rarely experience pain symptoms will not require treatment.
All children will try out walking on their toes during their development. If you see your child walking flat footed more than 25% of the time chances are they are experimenting with walking on their toes. If your child is walking on their toes most of the time but stands flat footed you can consider them a toe walker. There are many reasons for toe walking. It is important to discuss any concerns with your pediatrician but these explanations will give you some of the most common causes.