Lecture: Lower Limb 3: The Ankle Joint and Foot

Question 1

Why is dorsiflexion the most stable position of the ankle joint?

Answer 1

Trochlea of talus is wider anteriorly than posteriorly
during dorsiflexion, the anterior part of the trochlea moves between malleoli, spreading tibia/fibula
this increases their grip on the talus

Question 2

what lateral ligaments contribute to the stability of the ankle joint?

Answer 2

Anterior talofibular ligament
calcaneofibular ligament
posterior talofibular ligament

Question 3

what medial ligaments contribute to the stability of the ankle joint?

Answer 3

Deltoid ligament is attached to medial malleolus and fans out to attach to talus, navicular and calcaneus

Question 4

movements possible at the ankle joint?

Answer 4

dorsiflexion
plantarflexion
inversion
eversion

Question 5

Describe the dorsiflexors of the leg

Answer 5

Anterior compartment of the leg
Supplied by deep fibular nerve
supplied by anterior tibial artery

Question 6

Describe the plantarflexors of the leg

Answer 6

Posterior compartment of the leg
supplied by the tibial nerve
supplied by the posterior tibia artery

Question 7

Comment on ankle sprains

Answer 7

Mostly inversion injuries
ligaments relatively avascular so heal slow
predispose to dislocation
if ligament detaches from bone, grows back weaker

Question 8

what is the most common fracture to occur?

Answer 8

breaking off the head of the lateral malleolus

i.e. the head of the fibula as it is much weaker

Question 9

What are the joints involved in the foot?

Answer 9

Transverse tarsal joint, which is made up of:
 - talonavicular joint
 - calcaneocuboid joint
Naviculo-cuneiform joint
Tarsometatarsal joint
Metatarso-phalangeal joint
Interphalangeal joints

Question 10

What are the arches of the foot and what is their function?

Answer 10

Medial Longitudinal (MLA)
Lateral Longitudinal (LLA)
Transverse (TA)

help distribute weight
increase flexibility of the foot
act as springboards for propulsion during movemet

Question 11

Describe the MLA

Answer 11

comprised of calcaneus, talus, navicular, 3 cuneiforms and 3 medial metatarsals
MLA is higher and more important than LLA

Question 12

Describe the LLA

Answer 12

Calcaneus, cuboid and lateral 2 metatarsals

smaller as on outside of the foot

Question 13

describe the TA

Answer 13

Comprised of cuboid, 3 cuneiforms and bases of the 5 metatarsals

Question 14

what is the difference between passive and active support of the arches of the feet?

Answer 14

Passive - ligaments and the shapes of the bones

Active - intrinsic and extrinsic muscles of the foot