{HEAD ~ The frictional engagement} of {TAIL ~ each graft ligament} is temporally spaced apart from the frictional engagement of at least one other graft ligament 
of
{ HEAD ~ The frictional engagement } of { TAIL ~ each graft ligament } is temporally spaced apart from the frictional engagement of at least one other graft ligament
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH