His concept of jumping was for a skater to prevent the occurrence of core body rotation prior to springing into the air. He directed skaters to take off and continue "forward" in a straight line trajectory for as long possible. The initiation of rotation of the core body was suspended or delayed until reaching the apex of the jump. At this time the body would perform a "reverse under" and instantly turn from forward to backward initiated by turning the head in the direction of rotation. This causes the core body, if in an upright balanced position, to pivot around the landing hip and leg (rotate/spin around the long axis of the body). The speed of the rotation achieved in the air would depend on the tightness of the arms and legs folding into the "reverse under" position.
A skater's ability to complete the rotation in the air would allow a momentarily "pause" in the air to occur before the touch down of the landing foot. The key is that in the last half rotation in the air, the skater opens up their body position to stop (cancel) the rotation to achieve a controlled landing. The goal is for the skater to maintain the speed matching the takeoff velocity while landing backward. Mr. Lussi wanted the skater to exit on a straight line (controlled edge) rather than on a deeply hooked landing edge with the free leg swinging around in an tightly curving arc causing the residual centrifugal force of the jump's rotation to pull the body off balance.
Mr. Lussi emphasized the position of the shoulders and arms in the air. He stressed extending the arms from the shoulders to cause the delay in initiating the rotation in the forward trajectory, then, at the reverse under, the forearms folded to lay horizontal to the ice, flat palm over flat palm in at waist level, the elbows out to the sides (higher than the hands.)
Mr. Lussi did not want skaters to skate on a deep curving entry into a jump. He wanted skaters to enter into jumps on as straight a line as possible when taking off for all jumps as a means "to counteract the tendency to pre-rotate." Similarly, on the landing. he wanted the jump's exit edge to be on as straight a line as possible to maintain speed on the landing to avoid a sideways/deep curving edge with the free leg swinging around in a large arc causing the body to drastically lose speed or even resulting in an unchoreographed stop.