[Extension of the fingers. III. Morphologic and structural study].

The volar fascicles of the interosseous muscles possess two separate components: the proximal and glenoidal one, the distal and aponeurotic other. The armature of the dorsal aponeurosis is constituted the deep, the central and the collateral expansions of the extensor digitorum muscles, and the interosseous muscles, whom are added the lumbrical muscles. The deep expansions are constant and are fixed respectively at the basis of the first phalanx. The central and the collateral expansions constitute equally the central and the collateral, then terminal tendons, which are respectively fixed at the basis of the second and at the third phalanx. The unitive structures: dossiere, triangular and retinacular ligaments are intricate with this of the armature and render jointly the whole. All the concerned fascicles have the mechanical and histological characteristics of the tendon.