Dorsal interossei of the foot Dorsal interossei of the foot In human anatomy, the dorsal interossei of the foot are four muscles situated between the metatarsal bones. The four interossei muscles are bipenniform muscles each originating by two heads from the proximal half of the sides of adjacent metatarsal bones. The two heads of each muscle form a central tendon which passes forwards deep to the deep transverse metatarsal ligament. The tendons are inserted on the bases of the second, third, and fourth proximal phalanges and into the aponeurosis of the tendons of the extensor digitorum longus without attaching to the extensor hoods of the
Metacarpophalangeal joint Metacarpophalangeal joint The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the digits. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow cavities on the proximal ends of the proximal phalanges. Being condyloid, they allow the movements of flexion, extension, abduction, adduction and circumduction at the joint. Each joint has: The dorsal surfaces of these joints are covered by the expansions of the Extensor tendons, together with some loose areolar tissue which connects the deep surfaces of the tendons to the bones.