The bladder is adapted to apply {HEAD ~ a pressure} substantially perpendicular to {TAIL ~ the cavity wall} 
substantially perpendicular to
The bladder is adapted to apply { HEAD ~ a pressure } substantially perpendicular to { TAIL ~ the cavity wall }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL