Fibularis brevis

Fibularis brevis is a muscle located on the outer side of your lower leg. Its main function is to help you walk, run, and balance by pointing your foot downward and turning it outward. It attaches from the fibula bone (the smaller bone in your lower leg) to the fifth metatarsal bone (on the outside of your midfoot). When it contracts, it allows you to push off the ground and maintain stability during movement. Injuries to this muscle can cause pain and swelling on the outside of the ankle, often from ankle sprains or overuse.