An elongated means under tension is provided within the arms and about the joint members for maintaining {HEAD ~ the position} of the head end in given {TAIL ~ angular position} 
An elongated means under tension is provided within the arms and about the joint members for maintaining { HEAD ~ the position } of the head end in given { TAIL ~ angular position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL