Lecture 10 - Biomechanics of the Ankle and Foot (part 1)

Question 1

What are the 5 parts of the ankle/foot?

Answer 1

• tibia
• fibula
• 7 tarsal bones
• 5 metatarsal bones
• 14 palanges

Question 2

Which portion of the tibia is laterally rotated in the transverse plane with respect to the proximal end of the tibia?

Answer 2

the distal portion

Question 3

What does the distal portion of the tibia create?

Answer 3

a normal lateral, or external tibial torsion

Question 4

What does the lateral torsion of the tibia move?

Answer 4

the medial malleolus anteriorly

Question 5

How does tibial torsion change throughout development?

Answer 5

• Begin in slight lateral torsion or even medial torsion at birth
• Gradually progress to 20-40°of lateral torsion by adulthood

Question 6

What is tibial torsion measured by?

Answer 6

the angle between aline through the tibial plateaus and aline through the medial and lateral malleoli

Question 7

What does the fibular participate in?

Answer 7

ankle articulation

Question 8

What are the 3 parts of the fibula?

Answer 8

head, shaft and lateral malleolus

Question 9

What does the anterior shaft of the fibula give rise to?

Answer 9

extensor muscles of the foot

Question 10

What does the lateral surface of the fibula provide attachment to?

Answer 10

peroneal muscles

Question 11

What does the posterior surface of the fibula provide attachment to?

Answer 11

soleus and flexor hallucis longus

Question 12

Why is the plane of the articular surface of the lateral malleolus oriented laterally and inferiorly?

Answer 12

so that some of the load through the ankle can be shared by the fibula

Question 13

Which bone joins the foot to the leg?

Answer 13

the talus

Question 14

Are there any direct muscle attachments on the talus?

Answer 14

no

Question 15

What covers more than half of the talus’ surface?

Answer 15

articular cartilage

Question 16

What is the movement of the talus governed by?

Answer 16

forces applied to it by tibia, fibula and calcaneus

Question 17

What is the largest tarsal bone?

Answer 17

calcaneus

Question 18

What are the 3 functions of the calcaneurs?

Answer 18

• Sustains large impact forces during locomotion
• Provides along moment arm for Achilles tendon
• Transmits weight of the body from hind foot to forefoot

Question 19

What is the structural organization of the foot?

Answer 19

hindfoot, midfoot and forefood

Question 20

What does the hindfoot consist of?

Answer 20

talus and calcaneus

Question 21

What does the midfoot consist of?

Answer 21

the remaining tarsal bones

Question 22

What does the forefood consist of?

Answer 22

metatarsals and phalanges

Question 23

What are the 3 divisions of the forefoot?

Answer 23

first ray, second and third rays, fourth and fifth rays

Question 24

What comprises the first ray?

Answer 24

metatarsal of the big toe and the medial cuneiform bone

Question 25

What comprises the second and third rays?

Answer 25

second and third metatarsals and their proximal cuneiform bones

Question 26

What comprises the fourth and fifth rays?

Answer 26

fourth and fifth metatarsals