The origins and function of the interosseous muscles of the foot.

The dorsal and plantar interosseous muscles of the foot arise, not only from the metatarsal bones, but also from ligamentous tissue proximal to the tarsometatarsal joints. The interossei also take origin from the fascia of adjacent muscles, and the first dorsal interosseous muscle usually arises in part from a slip of the peroneus longus tendon. A means may thus exist to ensure that the interossei contract in a coordinated manner. Their positions and time of contraction during the gait cycle imply a possible role as stabilisers of the forefoot, rendering the tarsometatarsal joints rigid when weight is carried on the ball of the foot.