Amby Burfoot on Running Form

"At any rate, if your leg is perpendicular to the surface at footstrike (final illustration on right, at bottom panel), you're doing a lot of things right. You probably don't have to worry much about your stride."

Sounds right.  In line with the previous post, there seems to be a consensus emerging in the running world, a consensus driven by the minimalist movement. 

(He's got a nice shout-out to Pete Larson and Steve Magness.)