{HEAD ~ The grounding position} determining step may determine the grounding position of {TAIL ~ the second leg} so that the calculated second leg ZMP position is located in a contact area between the second leg and a ground 
{ HEAD ~ The grounding position } determining step may determine the grounding position of { TAIL ~ the second leg } so that the calculated second leg ZMP position is located in a contact area between the second leg and a ground
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH