ANATOMY AND BIOMECHANICS OF FOOT

1. ANATOMY AND BIOMECHANICS OF FOOT Presenter : Dr. SYED IMRAN Chair person : Dr. RUPAKUMAR C.S. Dr. SRINIVAS DEEP URS

2. The human foot is a complex structure adapted to allow orthograde foot stance and locomotion. • It is the only part which is in regular contact with the ground. iNTRODUCTION

3. Bones Joints Ligaments Arches Muscles ANATOMY :

4. Seven tarsal bones • Larger to support and distribute weight • Tarsus and metatarsus arranged to form intersecting longitudinal and transverse arches. Tarsus

5. Link between foot and leg through ankle joint. • Head : • Directed distally and inferomedially • Long axis is inclined inferomedially to articulate with proximal navicular surface • Plantar surface has 3 articular areas TALUS

6. talus

7. The most posterior is largest,slightly convex and rests on a shelf like medial projection,the sustentaculum tali. • Neck : • Constricted part • Long axis is directed downwards, forwards, medially. • Neck-body angle is 150

8. Body • Cuboidal and has five surfaces • Superior surface : Articulates with tibia • Wider anteriorly than posteriorly • Inferior surface : Articulates with calcaneum • Medial surface : Articulates with M.malleoli • Lateral surface : Articulates with L.malleoli • Posterior surface : Small

9. Tenous due to lack of muscle attachments • Extra-osseus supply from posterior tibial,doraslis pedis, peroneal Arteries. • A of tarsal canal anastomose with A of tarsal sinus to form a vascular sling under talar neck. Vascular supply :

10. a- Laterally A of tarsal sinus • b- A of tarsal canal • c- Deltoid branches

11. Neck : Capsular ligament of ankle joint, dorsal talonavicular ligament. • Lower non-articular part gives attachment to deep fibers of deltoid ligament. Attachments on talus

12. Largest tarsal bone • Projects posterior to tibia and fibula to act as a short lever for calf muscles. • Six surfaces • Vascular Supply : Medial and lateral calcaneal Arteries Calcaneum

13. Middle rough area on posterior surface receives insertion of tendocalcaneus and plantaris • Lower area is covered with dense fibrofatty tissue and supports body weight. • Lateral part : Origin on extensor digitorumbrevis, attachment of inf extensor retinaculum, stem of bifurcate ligament. Attachments on calcaneum :

14. Plantar Surface : Origin of abductor hallucis, flexor digitorumbrevies. Attachment of Plantar aponeurosis. • Origin of abductor digitiminimi • Medial margin of sustentaculum tali and gives attachment to Spring ligament ant , tibialis posteriorly in middle , deltoid ligament , talocalcaneal ligament posteriorly.

15. Boat shaped • Medial side between talus and cuneiforms • Distal surface 3 facets • Proximal surface articulates with talar head • Dorsal surface rough for attachment of ligaments • Plantar surface is non-articular. Navicular :

16. Tuberosity receives insertion of tibialis posterior • Plantar surface provides attachment to spring ligament • Calcaneonavicular part of bifurcate ligament is attached to lateral surface. Attachments on navicular

17. Lateral bone of distal row • Between calcaneus proximally and fourth and fifth metatarsals distally • Dorsal surface is rough for attachment of ligaments • Medial surface is articular for Lat. Cuneiform and non-articular. cuboid

18. Lateral surface occupies tendon of peroneuslongus • Poseromedial part of plantar surface provides insertion to a slip of tibialis posterior and origin of flexor hallucisbrevies. • Non-articular part of medial surface provides attachment to lateral limb of bifurcate ligament. Attachments of cuboid

19. Wedge like articulate with navicular proximally and bases of first to third metatarsals distally • Medial largest , intermediate smallest • Dorsal surface of lat and intermediate cuneiforms form base of wedge, wedge is reversed in med cuneiform,which is prime factor in shaping transverse arch. cuneiforms

20. Proximal surface has a piriform facet for navicular • Distal surface has a large kidney shaped facet for base of first metatarsal • Medial surface is rough and subcutaneous Medial cuneiform

21. Tibialis anterior on anteroinf surface of M.Cuneiform • Part of peroneuslongus inserted on lat surface • Intermediate cuneiform attachment to part of tibialis posterior • Plantar surface of lat cuneiform receives a slip of tibialis posterior and part of flexor hallucisbrevies. attachments

22. Lie distal in foot and connect tarsus and phalanges • Have shaft, proximal base and distal head • Convex dorsally and concave on plantar aspects metatarsals

23. Shortest and thickest • Gives attachment to tibialis anterior tendon medially and peroneus longus tendon on plantar aspect • Origin to first dorsal interosseus muscle First metatarsal

24. Longest • Base has four articular facets • Because of its length and steep inclination and position of base, it is at risk of stress overload and avasular phenomena. • Third MTP is relatively stiff and predisposes to stress fracture Second metatarsal

25. 14 phalanges • Two in hallux, three in other toes • Much shorter than hand • Compressed from side to side phalanges

26. Complex, three-bone joint • It consists of the tibial plafond (including the posterior malleolus articulating with the body of the talus), the medial malleolus, and the lateral malleolus. • The dome itself is wider anteriorly than posteriorly, and as the ankle dorsiflexes, the fibula rotates externally through the tibiofibularsyndesmosis, to accommodate this widened anterior surface of the talar dome. ANKLE JOINT

27. Passive : Medial and lateral ligaments, bony contours and capsular attachments • Dynamic stability by gravity , muscle action and ground reaction forces. • Stability requires continuous action of soleus and gastronemius. Stability of ankle

28. Ant and post articulations between talus and calcaneum “ Subtalar joint ” • Post articulation is talocalcaneal joint • Ant articulation is talocalcaneonavicular joint TALOCALCANEAL JOINT

29. Inversion by Tibialis ant and posterior • Eversion by Peroneus longus,breviesand tertius

30. Ankle stability is conferred by bony architecture and ligaments supporting ankle joint 1.Syndesmotic ligaments 2.Medial collateral ligaments 3.Lateral collateral ligaments LiGAMents

31. Syndesmotic ligaments

32. Ant talo-fibular ligament • Calcaneo fibular ligament : Resists inversion • Post talofibular ligament : Strongest and prevents posterior and rotatorysubluxationof talus Lateral collateral ligaments

33. Deltoid ligament : Superficial and deep part • Superficial fibers arise from medial malleolus and they attach into navicular, the neck of the talus, the medial border of the sustentaculumtali, and the posteromedialtalar tubercle. The tibiocalcaneal ligament is the strongest component of the superficial layer of the deltoid ligament, and it is responsible for resisting eversion of the calcaneus. medial collateral ligaments

34. Deep layer of the deltoid ligament is the primary medial stabilizer of the ankle joint. It is a short, thick ligament • The strongest fibers insert on the medial surface of the talus. • This ligament is virtually inaccessible from outside the joint, and it cannot be repaired unless the talus is displaced laterally or if the medial malleolus is inverted distally through fracture or osteotomy.

36. Medial longitudinal arch : • Ligaments resposible for stability • Most imp is Plantar aponeurosis, Spring ligament • Flexor hallucislongus, flexor digitorumlongus,abductorhallucis. • Tibialis ant and post : Inverting and adducting Arches of foot

37. Medial longitudinal arch

38. Medial Longitudinal Arch continued • Muscular Support • Intrinsic • Abductor Hallucis • Flexor DigitorumBrevis • Extrinsic • Tibialis Posterior • Flexor HallucisLongus • Flexor DigitorumLongus • Tibialis Anterior • Flexor DigitormLongus

39. Lateral part of plantar aponeurosis , long and short plantar ligaments • Peroneus longus tendon Lateral longitudinal arch

40. Lateral Longitudinal Arch continued • Muscle Support • Intrinsic • Abductor DigitiMinimi • Flexor DigitorumBrevis • Extrinisic • PeroneusLongus, Brevis & Tertius

41. Bases of 5 metatarsals , cuboid and cuneiforms • Stability by ligaments bind cuneiform and metatarsal bases and peroneuslongus tendon. Transverse arch • Ligament Support • Intermetatarsal Ligaments • Plantar Fascia • Muscle Support • All intrinsic muscles • Extrinisic • Tibialis Posterior • Tibialis Anterior • PeroneusLongus

42. The plantar fascia is a strong fibrous aponeurosis that runs from the calcaneus to the base of the phalanges. • It supports the arches and protects structures in the foot. Plantar fascia

43. muscles • Superficial Layer • Abductor Hallucis • Abductor DigitiMinimi • Flexor DigitorumBrevis

44. Middle Layer • QuadratusPlantae • Lumbricals

45. Deep Layer • Flexor HallucisBrevis • Adductor Hallucis • Transverse and Oblique Heads • Flexor DigitiMinimi

46. Interosseus Layer • Plantar Interossei • Dorsal Interossei

47. Most of motion of foot occurs at three synovial joints • Talocrural joint • Subtalar joint • Mid-tarsal joint • Most of motion occuring in hind foot biomechanics

48. Normal motion of the ankle joint is predominantly in the sagittal plane • Axis of the ankle joint as passing approximately 5 mm distal to the tip of the medial malleolus and 3 mm distal and 8 mm anterior to the lateral malleolus . a continuously changing axis of rotation. In dorsiflexion, the axis is inclined downward and laterally, whereas in plantar flexion, the axis is inclined downward and medially.

49. Plantarflexion (PF) and dorsiflexion (DF) occur about a mediolateral axis running through the ankle joint. The range of motion for plantarflexion and dorsiflexion is approximately 50° and 20°, respectively.

50. During dorsiflexion of the ankle, the intermalleolar distance increases approximately 1.5 mm as the fibula rotates externally and displaces laterally. • With the deltoid ligament, it contributes to the rotational stability of the talus Stability of the ankle joint in stance appears to be conferred mostly by articular congruity