The schemas are a set of 'types', each associated with a set of properties. The types are arranged in a hierarchy.he schemas are a set of 'types', each associated with a set of properties. The types are arranged in a hierarchy.
Inadequate stretching and warming up prior to exercise, or advancing your exercise program too quickly, or beginning a new exercise program, have all been known to cause symptoms. In some people, just vigorous walking or exercising on uneven ground is enough to exacerbate a flare-up of sciatica nerve pain.
Sciatica can be caused by a number of conditions that irritate or compress the sciatic nerve: 1  Piriformis syndrome: Tightening or spasm of the piriformis muscle can compress the nerve.  Trauma: A sports injury or fall can fracture the spine or tear a muscle and damage nerves.