At all times, {HEAD ~ the axes} of rotation of {TAIL ~ the handholds} are parallel to each other and extend along a plane that contains the axis of circumduction of the users shoulders 
At all times , { HEAD ~ the axes } of rotation of { TAIL ~ the handholds } are parallel to each other and extend along a plane that contains the axis of circumduction of the users shoulders
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH