The bladder expends while applying a pressure on the thermoplastic sheet against {HEAD ~ the wall} from the bottom portion to {TAIL ~ the top portion} 
to
The bladder expends while applying a pressure on the thermoplastic sheet against { HEAD ~ the wall } from the bottom portion to { TAIL ~ the top portion }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL