Bones of foot

Anatomical Description of The Bones and Joints of Foot

1. Bones and Joints of Foot  Dr. Mushfiqul Hoque Lecturer Dhaka National Medical College 

2. Tarsal Bones 

3. Tarsal Bones  7 in number Arranged in two rows, proximal and distal On the medial side between the two rows there is one bone, navicular Proximal row bones: Talus and calcaneus   Distal row bones: (from medial to lateral side) medial cuneiform, intermediate cuneiform, lateral cuneiform and cuboid  

4. Tarsal Bones  On the medial side, Navicular lies between talus and the three cuneiform bones. Calcaneus articulates with cuboid in front Talus lies upon the calcaneus and not by the side 

5. Metatarsal Bones  5 in number First metatarsal is the on the medial side which is the shortest and thickest. Second metatarsal is the longest 

6. Joints of the foot

7. Classification Joints of the foot: Intertarsal Tarsometatarsal Intermetatarsal Metatarsophalangeal interphalangeal 

8. Intertarsal Joints Subtalar or talocalcanean joint Talocalcaneonavicular joint  Calcanocuboid joint

9. Talocalcanean  Joints Plane synovial joint Between concave facet on the inferior surface of the body of talus and convex facet on the middle one-third of the superior surface of the calcaneum Movements: inversion and eversion 

10. Talocalcaneonavicular Joints Ball and socket type of synovial joint  Ball formed by head of talus Socket formed by navicular and calcaneum Movements: inversion and eversion 

11. Calcaneocuboid Joints Saddle type of synovial joint Take part in inversion and eversion 

12. Inversion and eversion of the foot Joints taking part: Subtalar ( talocalcanean ) Talocancaneonavicular Accessory joints:  Cancaneocuboid Talonavicular 

13. Smaller joints of the foot:  Tarsometatarsal, intertarsal, intermetatarsal joints are plane type of synovial joints Metatarsophalangeal joints are ellipsoid type of synovial joints Interphalangeal joints are hinge type of synovial joints 

14. Arches of the Foot

15. Arches of the foot Help in fast walking, running and jumping Help in weight bearing and providing upright posture Acts as a lever to propel the body in running, walking and jumping

16. Classification: Longitudinal:   Medial  Lateral Transverse: Anterior posterior 

17. Medial Longitudinal Arch Considerably higher More mobile and resilient than lateral Ends: anterior end is formed by heads of first and second metatarsal Posterior end forms by medial tubercle of the calcaneum Summit of the arch is superior articular surface of the body of talus Pillars are talus, navicular, 3 cuneiform and the first 3 metatarsal  main joint is talocalcaneonavicular 

18. Lateral Longitudinal Arch Characteristically low Limited mobility Built to transmit weight and thrust to the ground Anterior end is formed by the heads of the 4th and 5th metatarsals Posterior end is formed by lateral tubercle of the calcaneum Summit is at the level of articular facets of the superior surface of calcaneum Pillars are cuboid and 4th and 5th metatarsal 

19. Anterior Transverse Arch Formed by the heads of the 5 metatarsal bones Complete because both heads of 1st and 5th metatarsal come in contact with the ground

20. Posterior Transverse Arch Formed by greater part of tarsus and metatarsus Incomplete because only lateral end comes in contact with  the ground Forms a "half dome"

21. Factors responsible for maintenance of the arches Shape of the bones Intersegmental ties holding the different segments together Tie beams or bowstrings that connect the two ends of an arch Slings that keep the summit pulled up Suspension  

22. Intersegmental Ties: The Spring ligament for medial longitudinal arch The long and short plantar ligaments for the lateral longitudinal arch Interosseous muscles for transverse arch.  

23. Tie beams:  Plantar aponeurosis and muscles of the first layer of foot for longitudinal arches Adductor hellucis  for transverse arches

24. Slings:  Tendons of posterior compartment into the sole I.e. tibialis posterior, flexor hellucis longus, flexor digitorum longus for medial arch Peroneus longus and brevis for lateral arch Tendons of tibialis anterior and peroneus longus together form a sling to support both longitudinal arches Tendon of peroneus longus for transverse arches along with tibialis posterior.