As a result of this arrangement, rotations of {HEAD ~ the arm} 12 about the axis 9 lengthen or shorten {TAIL ~ each helical cord} 
As a result of this arrangement , rotations of { HEAD ~ the arm } 12 about the axis 9 lengthen or shorten { TAIL ~ each helical cord }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL