A chair is coupled to the shaft by a chair coupling member; a device carriage is coupled to the shaft by a carriage coupling member; and {HEAD ~ a footrest assembly} is coupled to {TAIL ~ the shaft} by a footrest coupling member 
A chair is coupled to the shaft by a chair coupling member ; a device carriage is coupled to the shaft by a carriage coupling member ; and { HEAD ~ a footrest assembly } is coupled to { TAIL ~ the shaft } by a footrest coupling member
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH