This document discusses the history and application of subtalar arthroereisis, a surgical procedure used to treat flatfoot deformity. It begins by describing different types of flatfoot and the goal of subtalar arthroereisis to restrict excessive joint motion while preserving some functionality. The document then details the evolution of various implant designs used for arthroereisis from the 1940s to present day. It provides classifications for implants and discusses their materials, locations of placement, fixation methods, and biomechanical effects. Potential indications, contraindications, and complications of the procedure are also summarized.