Biomechanics of Ankle joint- intended to share the powerpoint with first year undergraduate students at Kathmandu University School of Medical Sciences, Nepal.

1. Ankle and Foot
Saurab Sharma, MPT
Lecturer

2. Contents
 Anatomy review
•Joints of ankle and foot
•Ligaments
•Muscles
 Biomechanics: artho & osteokinematics
2

3. Functions of ankle and foot
 Absorb stress or shock – pliability of foot
 Propulsion of body in walking and
running- rigid foot
 Protection – sensation of sole of foot
3

4. Bones of ankle and foot
 26 bones and 2 sesamoids
 Forefoot
•Metatarsals- 5
•Phalanges- 14
 Midfoot
•5 tarsals
 Rearfoot
•Talus and Calcaneus
4

5. Ankle and foot
 Ankle- Talocrural joint
 Foot- joints and bones
including tarsals, meta
tarsals, phalanges
5

6. Parts of FOOT
 Fore foot
•Metatarsals and phalanges
 Mid Foot
•Remaining tarsal bones (with
transverse tarsal and inter
tarsal joints)
 Hind Foot
•Talus, calcaneus (with subtalar
joint)
6

7. Arthrology
7
Joints Type of joint Articular
component
Superior/ Proximal
Tibiofibular joint
Plane synovial
joint
Head of fibula
Posterolateral
aspect of lateral
condyle of tibia
Inferior/ Distal
Tibiofibular joint
Fibrous
Syndesmosis
Distal tibia and
fibula
Ankle/ Talocrural
joint
Hinge Malleolus of tibia
and fibula
Talus

8. Arthrology
Movements Planes Axis
Dorsiflexion/ Plantar
flexion
Sagittal plane Medio-lateral axis
Inversion/ eversion Frontal plane Antero-posterior axis
Abduction/ adduction Horizontal/
transverse plane
Vertical axis
Pronation • Dorsiflexion
• Eversion
• Abduction
Supination • Plantarflexion
• Inversion
• Adduction
8

9. Movements
9

10. Talocrural articulation (Mortise)
10Neumann 2010

11. Axis of Talocrural joint
11Neumann 2010

12. Osteokinematics
12Neumann 2010
• 1 Degree freedom of
motion around oblique
axis
• Supination and pronation
• Dorsiflexion - 15-25°
• Plantar flexion- 40-55°
Axis passes through tips of both
malleolus
Dorsiflexion
Plantarflexion

13. Arthrokinematics
13Neumann 2010

14. Closed Kinematic Chain
14Neumann 2010

15. Stability of Joints associated with Ankle
 Superior Tibio-fibular joint: Synovial
•Joint Capsule
•Popliteus
 Inferior Tibio-fibular joint: Syndesmosis
•Ant and post tibiofibular joint
•Interosseous ligament
15

16. Talocrural Joint- Ligaments
 Deltoid ligament
•Tibionavicular
•Tibiocalcaneal
•Tibiotalar
 Lateral Ligament
•Anterior talofibular
•Calcaneofibular
•Posterior talofibular
16

17. Subtalar Joint
 Pronation and supination
 Closed chain and open chain motion
 Important for walking uphill, standing with
feel kept wide apart, agility activities,
balancing on unstable surface
17

18. Subtalar Joint
 Articulation: posterior, middle
and anterior facets of
calcaneus and talus.
 Ligaments- medial, posterior
and lateral talocalcaneal
ligament, cervical ligament
 Calcaneofibular lig limits
excessive inversion, deltoid lig
limits eversion
18

19. Subtalar Joint Axis
19

20. Motion at Subtalar
20
anteriorly,
medially and
superiorly
Inversion = 2 X eversion?
(22.6°, 12.5°)
• Lateral malleolus
• Deltoid ligament

21. Transverse Tarsal (Mid tarsal) Joint
 Talonavicular + Calcaneocuboid joint
 Connects rearfoot and mid foot
 Equal through all the planes
 Role to adapt to variety of surface contours
21

22. Talonavicular joint
 Resembles a Ball and socket joint
 Provides substantial mobility to medial
longitudinal arch
 Much movement as inversion and eversion
(twisting)
 Head of talus (convex); proximal navicular
(concave)
22

23. Talonavicular joint (TNJ)
Spring ligament:
 Plantar calcaneo-navicular
 From sustentaculum talus
(of calcaneus) to medial
plantar surface of navicular
bone
 Forms floor and medial wall
of TNJ
23

24. Calcaneocuboid Joint
 Anterior (distal) surface of
calcaneus and proximal
surface of cuboid
 Dorsal calcaneocuboid
ligament
 Bifurcated ligament (Y-
shaped)
 Long and short plantar
ligament
24

25. Transverse Tarsal joint
 Axes of Rotation-
•Longitudinal- inversion/ eversion
•Oblique – combination of abduction+ dorsiflexion
and adduction+ plantarflexion
 Midfoot allows twice as much as supination
(20-25° of inversion) compared to pronation
(10- 15° of eversion)
25

26. Transverse Tarsal Joint:
Longitudinal axis (Inversion/Eversion)
26

27. Transverse tarsal joint
Oblique axis (DF/PF + Abd/Add)
27

28. Pronation of the foot
28

29. Supination of the foot
29

30. Medial Longitudinal Arch of foot
 Load bearing and
shock absorbing
 Keystone-
talonavicular joint
30

31. Passive support of Medial Longitudinal Arch
 Bones- 3 medial metatarsals, 3 cuneiforms,
navicular bone, talus, calcaneus
 TNJ, plantar fascia, spring ligament, 1st TMT
joint
31

32. Arch of Foot
Normal arch of Foot Dropped arch of Foot
32

33. Pes Cavus (Increased Arch)
33

34. Summary
 Ankle joint
 Subtalar joint
 Transverse tarsal joint
 Arch of foot
34

35. Foot posture and tibial rotation
 Hindfoot
Pronation
35

36. Foot posture and tibial rotation
36
Rarefoot
Supination

37. Distal Inter tarsal Joints
 Cuneonavicular Joint
 Cuboideonavicular Joint
 Intercuneiform and cuneocuboid joint
complex
Functions:
 Assist TTJ in pronation and supination
 Stability across midfoot
 Formation of transverse arch of foot
37

38. Distal Inter tarsal Joints
38

39. TMT joint (Lisfranc’s Joint)
 Separates forefoot and midfoot
 Base of metatarsals + distal surfaces of
cuneiform and cuboid
 Ligaments: dorsal, plantar and iterosseous
ligaments
 Capsule: well developed for 1st TMT joint
39

40. TMT joint
41

41. Function of Mid and forefoot
42

42. 1st MTP joint
44
(Flexor Hallucis Brevis)

43. Hallux Valgus
45

44. Intrinsic muscles
46
Windlass Effect

45. Summary!!!!
47