I received a nasty gash to my forearm while reaching across the prop to adjust the carb (15 stitches) on an Extra 300 w/.91 4-stroke. I got lucky and didn't have any nerve damage. Minnflyer gave good advice about moving to the rear once you've started the plane--it's just a good practice to get in the habit of.

Always try to maintain a healthy level of fear and you won't get bit. Never underestimate the PERMANENT damage you can incur from a spinning prop.