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