The extensor digitorum brevis is a small muscle on the top of your foot, toward the outside, just in front of the ankle. It helps lift and straighten your toes, mainly toes two through four, and it also supports the motions that help your foot clear the ground when you walk or run. It works closely with the longer muscles and tendons that come down the front of your shin and across the ankle, adding extra control and stability for toe extension.
Even though it is small, it matters for performance and comfort because your toes and forefoot play a big role in balance, push-off, and how efficiently you move. If this muscle is doing its job, you get smoother toe control, better foot placement, and often less “slapping” of the foot as it comes down. When it gets irritated or overworked, you may notice aching on the top of the foot, tenderness near the outer front of the ankle, or discomfort when lifting the toes or wearing tighter shoes.
In the context of training for visible abs, it’s not an ab muscle, but it still matters because strong, pain-free feet help you train consistently. If your foot mechanics are off or you’re dealing with top-of-foot pain, it can limit running, jumping, loaded carries, and even some leg exercises, which can reduce your overall calorie burn and training quality. Supporting your feet with smart progression, good footwear choices, and not overdoing high-impact volume helps you stay active enough to keep body fat moving in the right direction while you build the core strength that makes abs “pop” once leanness is there.