Specifically, the boundary conditions may be, for instance, the position and velocity of the center of gravity at the start point, and the velocity of {TAIL ~ the center} of gravity at {HEAD ~ the end point} 
Specifically , the boundary conditions may be , for instance , the position and velocity of the center of gravity at the start point , and the velocity of { TAIL ~ the center } of gravity at { HEAD ~ the end point }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD