Each extensor hood is triangular, with: the apex attached to the distal phalanx, the central region attached to the middle phalanx (index, middle, ring, and little fingers) or proximal phalanx (thumb), and each corner of the base wrapped around the sides of the metacarpophalangeal joint—in the index, middle, ring, and little fingers, the corners of the hoods attach mainly to the deep transverse metacarpal ligaments; in the thumb, the hood is attached on each side to muscles.