the Ankle and Foot
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joints | Main Anatomy
Index | The foot
Last updated 30 March 2006
Talocrural Joint (ankle joint)
- This is a hinge type of synovial joint.
- It is located between the inferior ends of the tibia and
fibula and the superior part of the talus.
- The talocrural joint can be felt between the tendons on
the anterior surface of the ankle as a slight depression,
about 1 cm proximal to the tip of the medial malleolus.
Articular Surfaces of the Talocrural Joint (p.
- The inferior ends of the tibia and fibula form a deep
socket or box-like mortise
into which the pulley-shaped trochlea
of the talus fits.
- The two malleoli and the inferior end of the tibia form
the three-sided mortise.
- The fibula has an articular facet on its lateral
malleolus, which faces medially and articulates with the
facet on the lateral surface of the talus.
- The tibia articulates with the talus in two places: (1)
its inferior surface forms the roof of the mortise, which
is wider anteriorly than posteriorly; and (2) the lateral
surface of its medial malleolus articulates with the
- The talus has three articular facets, which articulate
with the inferior surface of the tibia and malleoli.
- The trochlea of the talus is wider
anteriorly than posteriorly and slightly
concave side to side.
of the Talocrural Joint (p. 488)
- The talocrural joint is uniaxial; its main movements are
dorsiflexion and plantarflexion.
- When the foot is plantarflexed, some rotation, abduction,
and adduction of the ankle joint is possible.
- This occurs as in plantarflexion, the trochlea of the
talus rocks anteriorly in the three-side mortise. Since
the anteriorly it is not as wide, there is considerable
room for the ankle to move.
- During dorsiflexion the trochlea of the talus rocks
posteriorly in the three-sided mortise, and the malleoli
are forced apart because the superior articular surface
of the talus is wider anteriorly than posteriorly.
- The separation of the malleoli requires some movement of
the proximal tibiofibular joint. Thus, the range of
plantarflexion is greater than that of dorsiflexion, but
there is considerable variation in these movements.
Articular Capsule of the Talocrural Joint (p.
- The fibrous capsule is thin
anteriorly and posteriorly, but it is
supported one each side by strong collateral ligaments
(medial or deltoid and lateral ligaments).
- It is attached superiorly to the borders of the articular
surfaces of the tibia and malleoli.
- It is attached inferiorly to the talus close to the
superior articular surface, except anteroinferiorly,
where it is attached to the dorsum of the neck of the
Medial or Deltoid Ligament (p. 488)
- This strong ligament attaches the medial malleolus to the
tarsus (tarsal bones).
- The apex of the ligament is attached to the margins and
tip of the medial malleolus.
- Its broad base fans out and attaches to three tarsal
bones (talus, navicular, and calcaneus).
- The deltoid ligament consists of
four parts, which are named according to their
bony attachments: (1)
tibionavicular, (2) and (3) anterior and posterior
tibiotalar, and (4) tibiocalcanean ligaments.
- They strengthen the joint and hold the calcaneus and
navicular bones against the talus. In addition, they help
to maintain the medial side of the foot against the
Lateral Ligament of the Ankle (pp. 488-9)
- On the lateral side of the ankle there are three
ligaments that attach the lateral malleolus to the talus
- These are not as strong as the medial ligament.
- The three distinct parts of the lateral ligament are the anterior and posterior talofibular
ligaments and the calcaneofibular ligaments.
- The anterior talofibular
ligament is a flat band that extends
anteromedially from the lateral malleolus to the neck of
the talus. It is not very strong.
- The posterior talofibular
ligament is thick and fairly strong. It
runs horizontally medially and slightly posteriorly from
the malleolar fossa to the lateral tubercle of the
posterior process of the talus.
- The calcaneofibular ligament
is a round cord that passes posteroinferiorly from the
tip of the lateral malleolus to the lateral surface of
the calcaneus. It is crossed superficially by the tendons
of the fibularis (peroneus) longus and brevis muscles.
The Synovial Capsule of the Talocrural Joint
- The synovial capsule of the ankle joint lines the fibrous
capsule and occasionally projects superiorly for a short
distance into the inferior tibiofibular ligament between
the tibia and fibula.
- The synovial cavity of the ankle joint is somewhat
superficial on each side of the tendo calcaneus. Hence,
when the ankle joint is inflamed, the synovial fluid may
increase, causing swelling in these locations.
of the Talocrural Joint (pp. 489-90)
- This joint is very strong during dorsiflexion because it
is supported by powerful ligaments and it is crossed by
several tendons that are tightly bound down by
thickenings of the deep fascia called retinacula.
- The stability is also greatest in dorsiflexion because in
this position the trochlea of the talus fills the mortise
formed by the malleoli. Furthermore, the anterior part of
the trochlea forces the malleoli of the leg bones apart
Blood Supply of the Talocrural Joint
- The articular arteries are derived from the malleolar
branches of the fibular (peroneal) and anterior and
posterior tibial arteries.
Nerve Supply of the Ankle Joint (p.
- The articular nerves are derived from the tibial nerve
and the deep fibular (peroneal) nerve, a division of the
common fibular (peroneal nerve).
Subtalar (talocalcanean) Joint (p. 490-1)
- The subtalar (talocalcanean) joint is distal to the ankle
joint where the talus rests on and articulates with the
- The subtalar joint is a synovial joint between the
inferior surface of the body of the talus and the
superior surface of the calcaneus.
- It is surrounded by an articular
capsule, which is attached near the margins of
the articular facets.
- The fibrous capsule is weak but it is supported by
medial, lateral and posterior talocalcanean
- In addition, it is supported anteriorly by the interosseous talocalcanean ligament.
Movements of the Subtalar (talocalcanean)
Joint (p. 491)
- Inversion and eversion are
the main movements that occur at this joint.
- The joint also permits slight gliding and rotation that
assist with inversion and eversion of the posterior part
of the foot.
- Movements of the subtalar (talocalcanean) joint are
closely associated with those at the
talocalcaneonavicular and calcaneocuboid joints (parts of
the transverse tarsal joint).
The Talocalcaneonavicular Joint (p. 491)
- This joint is located where the head of the talus
articulates with the socket formed by the posterior
surface of the navicular bone, the superior surface of
the plantar calcaneonavicular ligament ("spring ligament"),
the sustentaculum tali, and the articular surface of the
- The talocalcaneonavicular articulation is a synovial
joint of the ball and socket type.
- The ball is the head of the talus and the socket
comprises two bones and two ligaments.
- The head of the talus has three facets, one for the
navicular and two for the calcaneus.
- All these articular surfaces are surrounded by a single
articular capsule that blends with the interosseous
talocalcanean ligament posteriorly.
- The talocalcaneonavicular joint is reinforced dorsally by
the dorsal talonavicular ligament,
a broad band connecting the neck of the talus and the
dorsal surface of the navicular bone.
- The plantar
calcaneonavicular ligament ("spring
ligament") is a triangular band that
extends from the sustentaculum tali to the
posteroinferior surface of the navicular bone.
- This ligament blends with the deltoid ligament medially
and forms part of the socket for the head of the talus.
- It also plays an important role in maintaining the
longitudinal arch of the foot.
Calcaneocuboid Joint (p. 491)
- This is a synovial joint between the anterior surface of
the calcaneus and the posterior surface of the cuboid.
- It is part of the transverse tarsal
- The dorsal calcaneocuboid ligament and plantar
calcaneocuboid ligament (short plantar ligament)
strengthen the capsule of the calcaneocuboid joint.
- The long plantar ligament
covers the plantar surface of the calcaneus. It passes
from the plantar surface of the calcaneus, including its
anterior and posterior tubercles, to both lips of the
groove on the cuboid bone.
- Some of its fibres extend to the bases of the second,
third, and fourth metatarsal bones, thereby forming a
tunnel for the tendon of the fibularis (peroneus) longus
- This muscle passes though the groove in the cuboid bone
to insert into the bases of the first metatarsal and the
adjoining part of the medial cuneiform bone.
- The long plantar ligament is important in maintaining the
arches of the foot.
- The plantar calcaneocuboid ligament (short plantar
ligament) is deep to the long plantar ligament. It
extends from the anterior aspect of the inferior surface
of the calcaneus to the inferior surface of the cuboid.
The Transverse Tarsal Joint (p. 491-2)
- This joint is the talonavicular
joint and the calcaneocuboid joint.
- These are separate joints but together they constitute
the transverse tarsal joint or mid-tarsal joint.
- They extend across the tarsus in almost the same
Movements of the Transverse Tarsal Joint
- Movements occurring at this joint produce inversion and eversion of the foot.
- During inversion, the foot is adducted and directed so
that its medial border is raised and its lateral border
is depressed, i.e., the sole of the foot is directed
towards the medial plane.
- In eversion, the foot is abducted and directed so that
the lateral border is raised and the medial border is
depressed, i.e., the sole of the foot is directed away
from the median plane.
- The strong medial (deltoid) ligament tends to prevent
overeversion of the foot; the weaker lateral ligaments
(with the assistance of the fibularis (peroneus) longus
and brevis muscles) tend to prevent overinversion of the