The ankle- Palastange

Question 1

Classification

Answer 1

Synovial hinge

Question 2

What is regulated at the ankle joint

Answer 2

The line of gravity

Question 3

Where does the line of gravity fall during normal standing

Answer 3

In front of the ankle joint

Question 4

How does the axis of the ankle joint lie and why is this significant
(think looking from the head down at the foot)

Answer 4

Axis is horizontal but oblique to the frontal plane by some 20-25degrees
The axis of the foot runs perpendicular to this
Means simultaneous movement of the knee and ankle can only occur when combined with movement at the subtalar joint

Question 5

What are the articular surfaces

Answer 5

Distal ends of the tibia and fibula and the body of the talus
(only the trochlear surfaces of the tibia and talus bear weight)

Question 6

Describe the features of the talus

Answer 6

Slightly broader in front that behind

Central longitudinal groove

Question 7

When is the ankle most stable and why

Answer 7

In extension (dorsiflexion)
Due the the wide talus being forced into the relatively narrower malleolar mortise and then tightly gripped by the malleoli and their ligaments

Question 8

When is the ankle least stable and why

Answer 8

In flexion (plantarflexion)
Narrower posterior talus is less tightly gripped by the malleolar mortise allowing some side to side movement

Question 9

Describe the joint capsule

Answer 9

Completely surrounds the joint
Is weak in front and behind to accommodate movementt
Strengthened laterally and medially by collateral ligaments

Question 10

Features of the medial collateral (deltoid) ligament

Answer 10

Strong triangular composed of several bands of fibres fused together
Deep parts- anterior and posterior tibiotalar bands
Superficial parts- tibionavicular band, tibiocalcaneal band

Question 11

What makes up the lateral collateral ligament

Answer 11

3 bands

• anterior and posterior talofibular ligaments
• calcaneofibular ligament lying in between the 2 above

Weaker than the deltoid

Question 12

What supports the ankle anteriorly and posteriorly

Answer 12

Anterior and posterior ligaments which are just really thickenings of the joint capsule

Question 13

Sectioning the lateral ligaments is associated with an increase in range of which movement of the ankle

Answer 13

Dorsiflexion

but not plantarflexion

Question 14

Blood supply

Answer 14

Malleolar branches from anterior tibial, fibular and posterior tibial branches

Question 15

Transverse stability of the joint depends on

Answer 15

Interlocking of articular surfaces

Question 16

When may transverse movement occur and what sequence of events must happen to allow this

Answer 16

When the foot is forcibly moved laterally (trauma)
Rupture of inferior TF ligaments- widening of mortise (diastasis)- talus can move from side to side- lateral malleoli may fracture

(All made worse if deltoid is sprained)

Question 17

If the fibula does not fracture at the lateral malleolus where else may a fracture occur and why is this important

Answer 17

Fracture may occur at the level of the fibular neck

Is important as not usually within the limits of an ankle x-ray so separate higher views must be taken to exclude

Question 18

What is the maximum range of movement at the ankle

Answer 18

Dorsi- and plantar-flexion may approach 90degrees

Question 19

What is the range of dorsiflexion

Answer 19

30 degrees

Question 20

What is the range of plantarflexion

Answer 20

50 degrees

Question 21

Limits to dorsiflexion

Answer 21

Tension in gastrocnemius and soleus as well as post part of deltoid ligament, calcaneofibular ligament and post joint capsule
Also wedging of the talus between the malleoli

Question 22

What is talipes equinus

Answer 22

Foot permanently fixed in plantarflexion due to shortening of gastrocnemius and soleus (cannot dorsiflex)

Question 23

Limits to plantarflexion

Answer 23

Tension in ant compartment muscles

Anterior part of deltoid, anterior talofibular ligament and ant joint capsule

Question 24

What happens to the range of motion used by the ankle with an increase in walking speed

Answer 24

ROM decreases, being mainly a decrease in plantarflexion

do not use full ROM during gait anyway

Question 25

Plantarflexors of the ankle

Answer 25

Superficial
-gastrocnemius, plantaris, soleus
Deep
-tibialis posterior, flexor digitorum longus, flexor hallucis longus

fibularis longus and brevis assist

Question 26

Muscles that dorsiflex the ankle

Answer 26

Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Fibularis tertius

Question 27

Muscles inverting the foot

Answer 27

Tibialis posterior and anterior

Question 28

Muscles everting the foot

Answer 28

Fibularis longus, brevis and tertius