Many cases of heel pain diagnosed as plantar fasciitis may actually involve other structures in the foot, especially the flexor digitorum brevis muscle on the bottom of the foot. The article outlines seven key signs that point toward flexor digitorum brevis involvement, including cramping, pain with toe flexion, changes in walking pattern, and worsening symptoms after activity. It emphasizes that proper diagnosis matters because different tissues respond to different treatments, and persistent heel pain often requires a more detailed evaluation than simply labeling it plantar fasciitis.