Jim...
LS in effect actually does sense the load, as when needed, the corkscrew takes effect, turning in one direction, helping to push the load down....other times, it may just oscillate with the base...
although there may be PF or LS mentions.....what is also referenced, as you may have seen at some events, we switch out agitators, as in this case, trying out a different agitator, lets say, a PF on an orbital tranny...and vice versa!