I had a coffee date with a guy who does a lot of Pilates, and Pilates is something that I am always encouraging students to do, because it is all about learning to engage the core abdominal muscles strongly and keep the rest of the body expanded and open simultaneously, a skill that is at the core of great acting. This guy was wearing these shoes that looked a little like some kind of platform sneakers, and it turned out they were special shoes, called MBT (Masai Barefoot Technology) shoes, designed with a curve in the sole. The effect of this is to force the person wearing them to use their abdominal muscles to stabilize themselves. Strengthening the core in this manner is sure to build the actor’s capability to release their vital energy onto their partner, and provide for more commanding performances. You may be able to find these with a google search, or you can drop me a line at firstname.lastname@example.org and I can send you info on where you can get them.
A related point is that when I talk to my students about choosing rehearsal clothes for their scene, I urge them to pay special attention to the choice of shoes. Shoes often define the physical relationship to the floor and the comportment of the spine, and everything else, really, follows form this, so it is a decision to give careful thought to.