The Extensor Hallucis Brevis is a small muscle on the top of your foot, closer to the outer side, that helps lift your big toe. It starts on the upper surface of the heel bone area (the front part of the calcaneus) and runs forward to attach near the base of the big toe. When it contracts, it assists in extending the big toe, meaning it pulls the toe upward toward the ceiling. It also helps stabilize the front of the foot during walking, running, jumping, and any movement where you push off the ground.
Even though it is small, it matters because the big toe is a major player in balance and power transfer. During a normal step, your body weight rolls over the foot and finishes through the big toe. For that to feel smooth and strong, the toe needs both mobility and control. The Extensor Hallucis Brevis contributes to that control, especially when you are lifting the toes to clear the ground while walking or when you are adjusting your foot position during faster movement.
If this muscle or the surrounding tendons get irritated, you might notice discomfort on the top of the foot near the big toe, stiffness, or a “tight” feeling when pulling the big toe up. It can be stressed by sudden increases in running volume, lots of hill work, tight shoes, or foot mechanics that overload the top of the foot.
For your six pack goals, this seems unrelated, but it affects training quality. Foot pain changes your gait, reduces how hard you can train legs and conditioning, and can limit intensity. Keeping your feet strong, mobile, and comfortable supports better workouts and faster progress overall.