Instead of a cushion, rigid side portions can be provided on {HEAD ~ the leg portions} to act as {TAIL ~ a support} 
to act as
Instead of a cushion , rigid side portions can be provided on { HEAD ~ the leg portions } to act as { TAIL ~ a support }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL