lower limb gross anatomy

1. •Ankle

2. LOs
• Describe the blood and nerve supply of
shoulder, elbow, hip and knee joint and the
mechanics of all large joints in the limbs with
emphasis on the special features that help to
maintain their stability and movements

3. • Describe the joints and movements of the
hand and foot with movements of fingers and
toes in relation to the insertions and actions
of the muscles and tendons which affect
them.

5. What is Ankle
• The ankle, or talocrural region, is the region
where the foot and the leg meet.
• The ankle includes three joints:
• the ankle joint proper or talocrural joint,
• the subtalar joint, and
• the Inferior tibiofibular joint.

6. • The term ankle is used to describe
structures in the region of ankle joint
complex
• Ankle joint complex include
–Ankle joint
–Subtalar joint
–Inferior tibio-fibular joint

7. • The bony architecture of the ankle
consists of :
• Tibia, Fibula and Talus and Calcaneum

10. • The true ankle joint is composed
of 3 bones:
• Tibia and fibula forming the superior part
–Tibia which forms the medial portion
–Fibula which forms the lateral portion
• Talus forming the inferior part

11. • Ankle joint is formed where the leg joins the
foot
• Talo-crural joint
• Crus [Latin word] is leg (knee to foot)
• Crura is plural of crus
• Crural is pertaining to leg

13. • It is a synovial hinge joint that connects the
distal ends of tibia and fibula with the
superior surface of talus bone
• The articulation between tibia and talus bears
more weight than between fibula and talus.
• The articular surface of tibia is referred to as
the plafond.
• Plafond (French for "ceiling"),

15. • The true ankle joint is
responsible for
• up (dorsiflexion) and
• down (planter flexion) motion
of the foot.

17. –dorsiflexion consists in the
approximation of the dorsum of
foot to the front of leg
–Angle decreases

19. –while in plantar flexion the heel is
drawn up and the toes pointed
downward
–The angle increases

20. • Beneath the true ankle joint is the second part
of the ankle, the subtalar joint, which consists
of the talus on top and calcaneus on the
bottom.
• The subtalar joint allows side to side motion
of the foot.

22. Talus bone
• Name the bones articulating with talus bone?
• Tibia
• Fibula
• Navicular bone
• Calcaneum

23. • Talus bone (Latin for ankle) is the first bone in
the tarsal bones in the foot. It forms the lower
part of the ankle joint.
• It also articulates with calcaneus below and
navicular in front.
• Through these articulations, it transmits the
entire weight of the body to the foot

24. • Talus is the second largest of the tarsal bones,
• It is also one of the bones in the human body
with the highest percentage of its surface area
covered by articular cartilage.

25. • Though irregular in shape, the talus can be
subdivided into three parts.
• Facing anteriorly, the head carries the
articulate surface for navicular bone, and the
neck, the roughened area between the body
and the head, has small vascular channels

28. • The body features several prominent
articulate surfaces:
• On its superior side is the trochlea tali flanked
by the articular facets for the two malleoli.
• The ankle mortise, the fork-like structure of
the malleoli, holds these three articular
surfaces in a steady grip, which guarantees the
stability of the ankle joint.

30. • The mortiseand tenon joint has been used for
thousands of years by woodworkers around
the world to join pieces of wood, mainly when
the adjoining pieces connect at an angle of
90°.
• In its basic form it is both simple and strong.

31. • Diagram of a mortise (on left) and tenon joint

33. • The superior articular surface of talus is
concave from side-to-side and convex anterio-
posteriorly
• It is broad anteriorly and narrow posteriorly

34. In full dorsiflexion
• The broad anterior area is grasped by ankle
mortise
• This requires widening of the malleolar gap
through
• Slight lateral rotation of fibula by stretching at
inferior tibiofibular syndesmosis and gliding at
superior tibiofibular joint

35. • Proximal or superior
tibiofibular articulation is
a plane synovial joint
between lateral condyle
of tibia and the head of
fibula
• The contiguous surfaces
of the bones present flat,
oval facets covered with
cartilage and connected
together by articular
capsule and anterior and
posterior ligaments

37. In full plantar flexion
• The posterior smaller area is in contact with
ankle mortise
• Even in this position eversion and inversions
are not possible in true ankle joint
• The true ankle joint is true hinge joint

40. • However, because the trochlea is wider in
front than at the back (approximately 5-6 mm)
the stability in the joint vary with the position
of the foot:

41. • With the foot dorsiflexed (toes pulled upward)
the ligaments of the joint are kept stretched,
which guarantees the stability of the joint;
• but with the foot plantarflexed (as when
standing on the toes) the narrower width of
the trochlea causes the stability to decrease

42. • Normally in standing and walking the ankle
joint is plantar flexed and remains unstable

43. • Behind the trochlea is a posterior process with
a medial and a lateral tubercle separated by a
groove for the tendon of flexor hallucis longus.
• Exceptionally, the lateral of these tubercles
forms an independent bone called os
trigonum or "accessory talus".

46. • On the bone's inferior side, three articular
surfaces serve for the articulation with
calcaneus, and
• several non-articular surfaces exist for the
attachment of ligaments

48. Blood supply
• The Talus bone lacks a good blood supply.
Because of this, healing a broken talus can
take longer than most other bones.

53. • most blood supplied to the head and neck of
the talus arises from the dorsalis pedis artery;
anastomosis within sinus tarsi & tarsal canal
form major blood supply to the talar head;

54. • artery of the sinus tarsi:
- peroneal artery
- from peroneal artery comes branches to
posterior process & branch to form artery of
sinus tarsi;
- dorsalis pedis artery
- supplies branches to dorsal talar neck &
branch to form artery of sinus tarsi;

55. • artery of sinus canal:
- branch of posterior tibial forms anastomotic
sling inferior to talus from which branches
arise to enter talar neck;
- deltoid branches usually arise from the
artery of the tarsal canal & supply the medial
third of the body;
- main artery supplying blood to the body of
the talus is the artery of the tarsal canal

57. • The major blood supply to the body was
provided by the artery of the tarsal canal.
• The deltoid and sinus tarsi vessels provided
significant minor sources of vascularity.

58. anastomoses around the ankle
• The ankle joint receives its blood supply form
malleolar rami of the anterior and posterior
tibial and peroneal arteries.

60. • One with a broken talus may not be able to
walk for many months without crutches and
will further wear a walking cast or boot of
some kind after that.

61. • Medial malleolus is a bony process extending
distally off the medial tibia.
• The distal-most part of fibula is called lateral
malleolus.
• Together, the malleoli, along with their
supporting ligaments, stabilize the talus
underneath the tibia

63. • The bony arch formed by the tibial plafond
and the two malleoli is referred to as the ankle
mortise.
• The joint surface of all the bones in the ankle
are covered with articular cartilage.

64. • Malleolus (Latin, "small hammer") is the bony
prominence on each side of the ankle.
• Each leg is supported by two bones, the tibia
on the inner side (medial) of the leg and the
fibula on the outer side (lateral) of the leg.

65. • The medial malleolus is the prominence on
the inner side of the ankle, formed by the
lower end of the tibia.
• The lateral malleolus is the prominence on the
outer side of the ankle, formed by the lower
end of the fibula.

67. Ligaments
• The ankle joint is bound by the strong
• Deltoid ligament
• and three lateral ligaments:
• Anterior talofibular ligament
• Posterior talofibular ligament
• Calcaneofibular ligament

68. • The major ligaments of the ankle are:
• Anterior tibiofibular ligament, which connects the
tibia to the fibula;
• Lateral collateral ligaments, which attach the fibula
to talus and calcaneus and gives the ankle lateral
stability; and,
• Deltoid ligaments, which connect the tibia to the
talus and calcaneus and provide medial stability.

70. Deltoid ligament
• Supports the medial side of joint
• Proximally , it is attached to the medial
malleolus
• Distally, it is attached to four places
– Sustentaculum tali of calcaneus
– Calcaneonavicular ligament
– Navicular tuberosity
– Medial surface of talus

72. • Deltoid ligament is a strong, flat, triangular
band, attached, above, to the apex and
anterior and posterior borders of medial
malleolus.

73. • The Deltoid ligament is composed of
– Anterior Tibiotalar Ligament,
– Tibiocalcaneal Ligament,
– Posterior Tibiotalar Ligament, and
– Tibionavicular Ligament.
• It consists of two sets of fibers, superficial and
deep

74. • Its middle portion, together with the
calcaneofibular ligament, binds the bones of
the leg firmly to the foot, and resists
displacement in every direction.
• Its anterior and posterior fibers limit extension
and flexion of the foot respectively, and the
anterior fibers also limit abduction

75. • Anterior and posterior talofibular ligaments
support the lateral side of the joint from
lateral malleolus to the posterior and anterior
ends of talus.
• Calcaneofibular ligament is attached at the
lateral malleolus and to the lateral surface of
calcaneum.
• Ligamentous support is more important
during plantar flexion

76. • Deltoid ligament is
very strong
• It usually resists a
force which fractures
the malleolus, to
which it is attached.

78. Tibiofibular ligament
• Though it does not span across the ankle joint
itself, the syndesmotic ligament makes an
important contribution to the stability of ankle.
• This ligament spans the syndesmosis (the
articulation between the medial aspect of distal
fibula and the lateral aspect of the distal tibia.
• An isolated injury to this ligament is often called
high ankle sprain.

79. Nerve supply
• The ankle joint receives its nerve supply from
deep peroneal, saphenous, sural and tibial
nerves.
• Occasionally, the superficial peroneal nerve
also supplies the ankle joint.

82. Syndesmosis
• Syndesmosis [Gr. syn with + desmos a band]
• It is a slightly movable articulation where the
contiguous bony surfaces are united by an
interosseous ligament, as in inferior
tibiofibular joint.

83. • If the syndesmosis is torn apart as result of
bone fracture, surgeons will sometimes fix the
relevant bones together with a syndesmotic
screw, temporarily replacing the syndesmosis.
• The screw inhibits normal movement of the
bones and, thereby, the corresponding joint.
When the natural articulation is healed, the
screw is removed

84. • The bony architecture of ankle joint is most
stable during dorsiflexion.
• A sprained ankle is more likely to occur when
the ankle is plantar-flexed.
• The classic ankle sprain involves anterior
talofibular ligament.

85. • The posterior talofibular ligament assists the
calcaneofibular in resisting the displacement
of the foot backward, and deepens the cavity
for the reception of the talus
• The anterior talofibular is a security against
the displacement of the foot forward, and
limits extension of the joint.

86. • Anterior talofibular ligament is also most
commonly-injured ligament during inversion
sprains.
• Another ligament that can be injured in a
severe ankle sprain is calcaneofibular
ligament.

88. • Symptoms of ankle fracture are similar to
those of ankle sprain i.e. pain or even more
severe.
• It is rare for ankle joint to dislocate in the
presence of ligamentous injury alone.
However, in fracture the talus can become
unstable and dislocate.
• People may complain of ecchymosis (bruising).
• Diagnosis is typically by X-ray.

89. • These components of ankle, along with the
muscles and tendons of lower leg, work
together to handle the stress the ankle
receives during walking, running and jumping.

90. Movements
• When the body is in the erect position, the
foot is at right angles to the leg
• dorsiflexion consists in the approximation of
the dorsum of the foot to the front of the leg,
while in extension the heel is drawn up and
the toes pointed downward
• The range of movement varies in different
individuals from about 50° to 90°

92. Axis
• Axis of rotation is not horizontal
• It slopes downward and laterally
• It passes through the lateral surface of talus
just below the apex of the triangular articular
area and
• through the medial surface at a higher level
just below the concavity of the comma-
shaped articular area

94. • The transverse axis about which movement takes
place is slightly oblique
• It passes through the malleoli just above their
apices
• Lateral, posterior, inferior (plantar) to medial,
anterior, superior (dorsal)
• 8 degree from transverse plane
• 82 degree from sagittal plane
• 20 to 30 degree from coronal plane

95. • Dorsiflexion

97. • The axis changes during movements, for the
upper convexity of talus is not the arc of a
circle rather of an ellipse

98. • Plantar flexion

100. • This axis corresponds to the deviation of
malleoli in ankle mortise
• Largest deviation from the sagittal plane so
the dominant movements will be dorsiflexion
and plantar flexion
• Frontal plane movements relatively less

102. • The malleoli tightly embrace the talus in all
positions of the joint, so that any slight degree
of side-to-side movement which may exist is
simply due to stretching of the ligaments and
slight bending of the body of the fibula
• The superior articular surface of the talus is
broader in front than behind.

103. • In dorsiflexion, therefore, greater space is
required between the two malleoli.
• This is obtained by a slight outward rotatory
movement of the lower end of the fibula and a
stretching of the ligaments of the syndesmosis;
• this lateral movement is facilitated by a slight
gliding at the proximal tibiofibular articulation,
and possibly also by the bending of the body of
the fibula

105. • The movements of inversion and eversion of
the foot, together with the minute changes in
the form by which it is applied to the ground
or takes hold of an object in climbing, etc., are
mainly effected in the tarsal joints

106. Transverse tarsal joint
• The joint which enjoys the greatest amount of
motion being that between the talus and
calcaneus behind and the navicular and cuboid in
front.
• This is often called the transverse tarsal joint,
and it can, with the subordinate joints of the
tarsus, replace the ankle-joint in a great measure
when the latter has become ankylosed

107. • The transverse tarsal joint or midtarsal joint is
formed by the articulation of calcaneum with
cuboid, and the articulation of talus with
navicular bone
• The movement which takes place in this joint is
more extensive than that in the other tarsal
joints, and consists of a sort of rotation by means
of which the foot may be slightly flexed or
extended, the sole being at the same time carried
medially (inverted) or laterally (everted)

109. • Extension of the foot (plantar flexion) upon
the tibia and fibula is produced by the
Gastrocnemius, Soleus, Plantaris, Tibialis
posterior, Peronæi longus and brevis, Flexor
digitorum longus, and Flexor hallucis longus;
• dorsiflexion, by the Tibialis anterior, Peroneus
tertius, Extensor digitorum longus, and
Extensor hallucis longus

111. • The line of gravity passes behind the cervical
vertebrae, in front of the thoracic vertebrae,
behind the lumbar vertebrae, behind the hip
joint, in front of the knee joint, one to two inches
in front of the ankle joint.
• Stability requires continuous action by soleus
• Stability increases with leaning forward involving
gastrocnemius and vice versa

112. • In backward sway
• When line of gravity becomes posterior to the
transverse axis of ankle joints
• The plantar flexors relax and the dorsiflexors
contract

113. • From the upright position, with the foot at
right angle to the leg, active plantar flexion of
about 200 is produced by gastrocnemius and
soleus, assisted by long flexor tendons and the
long and short peronei.

114. • Active dorsiflexion of about 100 is produced by
tibialis anterior, the long toe extensors and
peroneus tertius.
• The degree of passive movements possible is
approximately double the above

115. • It should be clear that the Extensor digitorum
longus and Extensor hallucis longus are
extensors of the toes, but flexors of the ankle;
and that the Flexor digitorum longus and
Flexor hallucis longus are flexors of the toes,
but extensors of the ankle