No arch, no wide grip! The arch in a bench press achieves a number of things that allow you to bench press more weight safely. The most important part of the arch is the upper back. This is called thoracic extension, and this is paired with another movement of the shoulder blades, which is called scapula retraction (pulling your shoulder blades back). This position is what you need if you want to be able to comfortably position your arms in a wide grip for a bench press, and if you’re not archin