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