It is therefore {HEAD ~ an object} of {TAIL ~ this invention} to provide a device that relieves the stress on the back and buttocks when the user is sitting in a chair to which the device has been attached 
of
It is therefore { HEAD ~ an object } of { TAIL ~ this invention } to provide a device that relieves the stress on the back and buttocks when the user is sitting in a chair to which the device has been attached
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH OTH OTH OTH