An embodiment of the present invention resides in {HEAD ~ a polygonal rib structure} wherein {TAIL ~ the polygonal rib structure} is a shock absorbing member 
wherein
An embodiment of the present invention resides in { HEAD ~ a polygonal rib structure } wherein { TAIL ~ the polygonal rib structure } is a shock absorbing member
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH