{HEAD ~ The arm} rotates about {TAIL ~ axis A} with an angular range of rotation of the order of 60 degrees 
rotates about
{ HEAD ~ The arm } rotates about { TAIL ~ axis A } with an angular range of rotation of the order of 60 degrees
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH