Back in the 1800s, strongmen used partial range of motion (ROM) lifts, like the silver dollar deadlift, to impress the crowds with their feats of strength… because they knew they could lift more weight. The crowds didn’t know this, but the strongmen sure did. Show-offs.
Partial ROM lifts returned to fashion in the 1970s, when power racks, which allow the athlete to start the lift at various heights and reduce the ROM, became commonplace.
Ever since, lifters have used partial ROM lifts as a method to bust through plateaus and build strength.