A similar set of components may be used to measure {HEAD ~ rotation} about {TAIL ~ the other axes} 
A similar set of components may be used to measure { HEAD ~ rotation } about { TAIL ~ the other axes }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL