Definitions of running (was RE: RE: Complaining)

["Thomas R. Holtz, Jr." <tholtz@umd.edu>]

> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of 
> David Marjanovic
> Sent: Tuesday, April 30, 2013 2:58 PM
> To: dinosaur@usc.edu
> Subject: Aw: RE: Complaining
> 
> > Since when did a full-suspension phase qualify as a "true run"?
> 
> ...What? I thought "all fours off the ground at the same time" is the _most_ 
> restrictive definition of "run" out there?

Actually, it WAS the most traditional definition.

But the current definition is a dynamic one: running requires a compliant gait 
(that is, the limb is most compressed at the midpoint of the stride). Compare 
walking and jogging in place at exactly the same pace to understand the 
difference.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA