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.
If you have flat feet, your arches are low or maybe even absent. Flat Feet and Overpronation. Flat feet are often associated with excessive pronation, which is the action that causes the foot's arch to descend down and inward (flattening) as the foot strikes the ground. Pronation is a normal and necessary foot motion.