{HEAD ~ The front wheel} is a caster wheel pivotally attached to {TAIL ~ an arm} directly or indirectly connected to the wheelchair frame 
{ HEAD ~ The front wheel } is a caster wheel pivotally attached to { TAIL ~ an arm } directly or indirectly connected to the wheelchair frame
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH