The Ankle and Foot Joints

1. The Ankle and Foot Joints

2. Function of the foot • Provide a stable platform • Generate propulsion • Absorb shock

3. Bones • Ankle + foot = 28 bones • foot = 26 bones • Leg: tibia, fibula • Foot: • Tarsals (7): talus, calcaneus, navicular, cuboid, and cuneiforms (3) • Metatarsals (5) • Phalanges (14)

4. Joints • Tibiofibular: • articulation between tibia and fibula • amphiarthrodial joint • Ankle joint • Talocrural • articulation between talus and tibia; talus and fibula • classified as a ginglymus

5. Joints • Subtalar joint • articulation between talus and calcaneus • classified as arthrodial (gliding) joint • Transverse tarsal joint • articulation between talus, navicular, calcaneus and cuboid bones • classified as arthrodial joint

6. Joints • Tarsometatarsal • tarsal bones and metatarsal • classified as arthrodial (gliding) joints • Metatarsophalangeal • metatarsals and phalanges • classified as condyloid • Interphalangeal joints (proximal and distal) • phalangeal bones • ginglymus

7. Arches of the foot • Medial longitudinal arch • calcaneus, talus, navicular, cuneiforms (3), and medial metatarsals (3). • Lateral longitudinal arch • calcanueus, cuboid, lateral metatarsals (4 & 5) • Transverse arch • across metatarsals

8. Classifying Arch Type • Pes Planus: Flat foot • Pes Cavus: High Arch • Normal

9. Movements • Ankle joint • dorsiflexion: “raising the toes” • plantarflexion: “point the toes” • Subtalar & Transverse tarsal joints • Calcaneal inversion and eversion • Interphalangeal joints • flexion • extension

10. Movements • Supination • inversion • plantar flexion • adduction • Pronation • eversion • dorsiflexion • abduction

11. Summary • Bones of the foot: • tarsals, metatarsals, phalanges • Joints of the foot and ankle • talocrural (ankle) • subtalar • transverse tarsal • metatarsalphalangeal • interphalangeal • Movements • dorsiflexion/plantarflexion (ankle joint) • inversion/eversion (subtalar & transverse tarsal) • flexion and extension of toes about the interphalangeal joints

12. Muscles • Plantar flexors • Dorsi flexors • Evertors • Invertors

13. Plantar Flexors • Gastrocnemius • Flexor digitorum longus • Peroneus longus • Plantaris • Soleus • Tibialis Posterior

14. Dorsiflexors • Tibialis anterior • Peroneus tertius • Extensor digitorum longus

15. Invertors • Tibialis anterior • Tibialis posterior • Flexor hallucis longus

16. Evertors • Peroneus longus • Peroneus brevis • Peroneus tertius • Extensor digitorum longus

17. Extensor digitorum longus (p44) • Origin • lateral condyle of tibia • upper 3/4 of anterior aspect of fibula • Insertion • superior aspect of foot, middle and distal phalanges of four lesser toes • Action • Extension of four lesser toes • dorsal flexion • eversion

18. Extensor hallucis longus (p45) • Origin • fibula, middle aspect of anterior fibula • Insertion • superior aspect of foot, base of distal phalanx of great toe • Action • dorsiflexion • extension of great toe

19. Peroneus tertius (p46) • Origin • fibula, anterior-lateral surface of lower 1/3 of fibula • Insertion • superior aspect of foot, base of fifth metatarsal • Action • Eversion • Dorsal flexion

20. Tibialis anterior (p47) • Origin • Lateral condyle of tibia • Upper two-thirds of anterior-lateral aspect of tibia • Insertion • plantar surface of 1st (medial) cuneiform and 1st metatarsal • Action • Dorsal flexion • inversion

21. Peroneus brevis (p48) • Origin • fibula, lower two-thirds, lateral aspect • Insertion • 5th metatarsal tuberosity • Action • eversion

22. Peroneus longus (p49) • Origin • lateral surface of tibia • fibula, upper two-thirds of lateral aspect of fibula • Insertion • inferior aspect of foot, 1st cuneiform and 1st metatarsal bones • Action • Eversion • Plantar flexion

23. Flexor digitorum longus (p50) • Origin • tibia, middle third, posterior aspect • Insertion • plantar surface of foot, distal phalanx of each of the four lesser toes (no big toe) • Action • ‘toe’ flexion • plantar flexion

24. Flexor hallucis longus (p51) • Origin • fibula, lower two-thirds, posterior aspect • Insertion • plantar aspect of foot, base of distal phalanx of big toe (‘hallucis’) • Action • ‘big toe flexion’ • inversion

25. Gastrocnemius (p52) • Origin • medial and lateral epicondyle of the femur • Insertion • posterior surface of calcaneus • Action • plantar flexion • knee flexion

26. Soleus (p54) • Origin • upper 1/3 posterior shaft of fibula • posterior surface of head of fibula • popliteal line • middle 1/3 of medial border of tibia • Insertion • Posterior surface of the calcaneus • Action • Plantar flexion

27. Note • Gastrocnemius and Soleus muscles have a common tendon/insertion (calcaneal tendon or Achilles tendon) • Some texts refer to the combination of the gastrocnemius and soleus as the triceps surae (three headed muscle).

28. Plantaris (p53) • Origin • posterior surface of lateral epicondyle of femur • Insertion • posterior surface of calcaneus • Action • plantar flexion

29. Tibialis Posterior (p55) • Origin • middle 1/3 of posterior-lateral surface of tibia • middle 1/3 of posterior-medial surface of fibula • Insertion • plantar surface of foot, lower inner surfaces of navicular, cuneiforms, and 2nd & 3rd metatarsals • Action • plantar flexion • inversion

30. Summary of muscles • Plantar flexors • gast., sol., flx digitorum long., per longus, tib post, plantaris • Dorsi flexors • tib ant, per tertius, ext dig long • Evertors • per longus, brevis, tertius, ext dig longus • Invertors • tib ant & post, flx hallucis long