Metatarsophalangeal joint

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Scheme of human foot bones. The metatarsophalangeal joints are located between the upper ends of the metatarsal bones shown in yellow and the first phalanges of the toes shown in green.

The metatarsophalangeal joints ( Articulationes metatarsophalangeae ) are the joints between the heads of the metatarsal bones ( caput ossis metatarsi ) and the respective base of the first phalanx of the toe bones ( base phalangis proximalis ). In ungulates , the metatarsophalangeal joints are called the fetlock joints .

The respective base of the proximal phalanx forms the joint socket, by the faserknorplig reformed ligament plantar is completed. The joint socket is surmounted on the sole of the foot by the significantly larger joint head of the metatarsal head. Each metatarsophalangeal joint is stabilized by a collateral ligament on both sides . On the dorsum of the foot, the metatarsophalangeal joints are covered by the dorsal aponeurosis . The metatarsophalangeal joints are ball- and- socket joints , but their range of motion is limited. The dorsiflexion enough active to an angle of 70 °, passive to 90 °. The degree of flexion extends actively up to an angle of 50 °, passively up to 50 °. When standing, the joints are in slight dorsiflexion. Sideways movements are good for small children, but hardly possible for adults

X-ray of the toe bones

On the sole side of the first metatarsophalangeal joint in humans, there are two small sesamoid bones that are embedded in the tendons of the abductor hallucis and adductor hallucis muscles . In quadruped mammals, there are two sesamoid bones per toe ray, the proximal sesamoid bone , to which the interossei muscles attach and which serve as a slide bearing for the deep flexor tendon on the sole side of the metatarsophalangeal joint .

Hallux valgus is a common misalignment of the first metatarsophalangeal joint .

literature

  • Walther Graumann, Rolf Baur: the musculoskeletal system. In: Compact Textbook Anatomy. Vol. 2, Schattauer, Stuttgart 2004, ISBN 3-7945-2062-9 , pp. 200-201.
  • Franz-Viktor Salomon: musculoskeletal system . In: Franz-Viktor Salomon et al. (Hrsg.): Anatomie für die Tiermedizin . Enke-Verlag Stuttgart, 2nd ext. Edition 2008, ISBN 978-3-8304-1075-1 , pp. 22-234.