The outer part 12b of the base joint is fixed to {TAIL ~ one end} of {HEAD ~ a lower arm} 14 
The outer part 12b of the base joint is fixed to { TAIL ~ one end } of { HEAD ~ a lower arm } 14
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH