I guess I'm looking for a better explanation of the "monolithic margin", because I'm not sure I've got it. Can Tube or anyone else please post some photos with a nice big red line on the monolithic margin of footprints made with stompers, footprints from the Elbe trackway, and footprints from real feet (that of course, lack the monolithic margin)? That would help me a lot, and I assume others too.
Suppose you have a rigid Wallace-style prosthetic. You put in all your energy into the plantar surface, carving out the toes and such. Suppose you carve your toes close together, and don't cut spaces between the toes. This lowers the chance of a toe breaking off, as there is a great deal of leverage when the toes are leaving the track. This accounts for the "digging" seen with the toes in some tracks.
Suppose you start with dimensional lumber, which starts out life flat on both sides. Since the track information is largely created by the plantar surface, you see no need to carve or texture the dorsal surface. Couple that with no gaps between the toes, and you get a "monolithic" or unbroken leading edge of your prosthetic on the dorsal surface.
In most cases where the prosthetic does not sink deeply into the substrate, you will be fine, as were most of Ray Wallace's tracks. When the prosthetic sinks more deeply into the substrate, the UNBROKEN LEADING EDGE OF THE DORSAL SURFACE is what defines the leading edge of the track AT GRADE.
In a track made by a human, the front edge of the track will be more ~scalloped~ as the leading edges of toes are rounded, and substrate is squishing up in between the toes.
In my opinion, Ray Wallace figured out through trial and error that cuts made between the toes weaken the prosthetic, and result in toes breaking off, due to the large leverage force at push-off.
I have numerous photos and further explanation on my page found here:
http://orgoneresearch.com/2009/10/19/fake-feet-and-monolithic-margins-2/
If this explanation is insufficient, please advise, and I'll break out the red crayons.