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.
Symptoms that may occur in some persons with flexible flatfoot include: 1  Pain in the heel, arch, ankle or along the outside of the foot. 2  Rolled-in ankle (overpronation) 3  Pain along the shin bone (shin splint)  General aching or fatigue in the foot or 1  leg. Low back, hip or knee pain.