{TAIL ~ The device} thereby maintains the lower end of {HEAD ~ the spine} in an erect position 
{ TAIL ~ The device } thereby maintains the lower end of { HEAD ~ the spine } in an erect position
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH