It turned out to be a column vs row vector issue. For some reason using the fill method above with flipud with the original column vectors doesn't work, but transposing the original variables then using fliplr does. Go figure. Here's the code in case it helps someone else:
x = linspace(0,100, 101);
mean = torqueRnormMean(:,DOF)';
meanPlusSTD = torqueRnormMean(:,DOF)' + torqueRnormStd(:,DOF)';
meanMinusSTD = torqueRnormMean(:,DOF)' - torqueRnormStd(:,DOF)';
fill( [x fliplr(x)], [meanPlusSTD fliplr(meanMinusSTD)], 'k');
alpha(.25);
plot(x, mean, 'k', 'LineWidth', 2)
plot(x, meanPlusSTD, 'k')
plot(x, meanMinusSTD, 'k')
Note that I removed the dotted line and just used thin vs. thick lines to denote standard deviation and mean. I did this because the line style was inconsistent. This code is in a loop where DOF runs from 1:9, and in some of the subplots both std curves would be dashed and in some just the top or bottom. It didn't matter enough to me to have them dashed so I kept it simple. Now this is an example of the graph I get: