This exact same concept can be found in the letters of Paul and John as well. (redeeminggod.com)
We've taken the exact same concept but shrunk it down to a designed kitchen appliance. (foodnavigator.com)
This exercise, while using the exact same concept of locking down the lower legs, is done using only a bar and a power rack (and a barbell pad, if you've got one), which makes it a lot more accessible. (hardgainermusclebuilding.com)