Benefits of the Floor Press
The floor press is one of the foundation movements of benching and the floor press been around far longer than the bench press (The bench press was invented during the mid 19th century).
So how does a floor press improve your strength for benching in competition ? Floor press takes many of the assistance muscles out of the lift that would normally be used in a powerlifting bench press, in particular when the floor press is done with straight legs there is no chance of leg drive and no arch. By removing leg drive you are isolating the upper body in particular the triceps to develop massive upper body power.
With the limited range of motion, and pause with the elbows at 90 degrees the Floor Press
will help develop explosive power through the mid range of the lift with great carry over to a full range lift on the Bench Press.
Floor Press is easy to spot, making it a good choice when your options for spotters is limited, allowing you to push bigger weights in a safe way instead of limiting your weight on the bench press due to safety reasons. The Floor Press also has the added benefit of being easy on the shoulders making it a good exercise to use during recovery from shoulder injury.
This Floor Press video shows how to do a floor press with the more common knees bent version.