Hammer's finger is a deformation characterized by a flexion of the proximal interphalangeal joint and a dorsal hyperaesthesia of the metatarsal-pharyangial articulation and the distal interphalangeal joint that has the finger like the goblet of the piano key from which the name comes from. In addition to aesthetic defect, well visible, these deformities cause inflammation, severe pain and redness at the point of contact with the footwear. Friction leads to the formation of dorsal or plantar calluses that can result in ulcerative lesions and infections.
