Ran across this forum looking for info on "cripple walls". My neighbor, here in the north Los Angeles area (Highland Park/Eagle Rock), was filling out an earthquake insurance form and asked me what a cripple wall was. Didn't know. Do now, he doesn't have one, but I do. Since I'm doing some fairly major plumbing and wall repair now I have a good section of it exposed and think it should be earthquake proofed while I'm at everything else. Why the heck not, huh? ;-)
fyi, a cripple wall is a short, less than 1 story, wall between the foundation and the first floor. The older ones are generally not reinforced, and even if the house is bolted down can fail catastrophically in a quake. We're due for the Big One, and my house is on a hill. Time to get ready.