The third arm has {HEAD ~ at least one resiliently deformable lobe section} between {TAIL ~ its distal and proximal ends} to allow movement of the proximal end relative to the distal end of the third arm 
between
The third arm has { HEAD ~ at least one resiliently deformable lobe section } between { TAIL ~ its distal and proximal ends } to allow movement of the proximal end relative to the distal end of the third arm
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH