{HEAD ~ A foot bar support assembly} movably carried by {TAIL ~ each} of the outwardly open slots supports the foot bar 
movably carried by
{ HEAD ~ A foot bar support assembly } movably carried by { TAIL ~ each } of the outwardly open slots supports the foot bar
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH