10.1 Osteology and Arthrology of the Lower Leg and Foot

Question 1

Which three bones articulate to form the ankle joint? What is the fancy name for this joint?

Answer 1

• Talus
• Fibula
• Tibia

AKA talocrural joint (crus = leg)

Question 2

Active recall the tarsal bones

Answer 2

Tiger Cubs Need MILC

• Talus
• Calcaneous
• Navicular
• Medial cuneiform
• Intermediate cuneiform
• Lateral cuneiform
• Cuboid

(This is true by the way; tigers are mammals)

Question 3

What are the bones within the midfoot, hindfoot, and forefoot?

Answer 3

Hindfoot: talus and calcaneus

Midfoot: Navicular, 3x cuneiforms and cuboid

Forefoot: Metatarsals and phalanges

Question 4

What is the anatomical name for the big toe?

Answer 4

Hallux

Question 5

What phalanges do each digit of the foot contain?

Answer 5

Hallux: Proximal, distal
All others: proximal, intermediate, distal

Question 6

The ankle joint is an open mortise and tenon joint. What is meant by this?

Answer 6

• Woodworking phrase: tenon inserts into mortise (ikea furniture)
• Opening in mortise enables the foot to move in the sagittal plane

Question 7

Describe the structure of the inferior syndesmosis joint between the tibia and fibula

Answer 7

• Interosseus membrane
• Anterior inferior tibiofibular ligament (AITFL)
• Posterior inferior tibiofibular ligament (PITFL)

Question 8

What are the retinaculi of the foot? What are they made of, and what is their function? Give three examples

Answer 8

• Strong fascial bands that encase and protect ligaments
• Function to prevent bowstringing of tendon
• Three examples are the flexor (S/I), extensor (S/I), and fibular retinaculi

Question 9

What are the three lateral collateral ligaments of the foot?

Answer 9

• Calcaneofibular
• Anterior talofibular
• Posterior talofibular

Question 10

What are the four medial collateral ligaments of the foot?

Answer 10

• Ant/post tibiotalar
• Tibiocalcaneal
• Tibionavicular

Question 11

Which ligament does talocalcaneonavicular joint rest on?

Answer 11

Plantar calcaneonavicular ligament

Question 12

Which two joints comprise the midtarsal joint complex?

Answer 12

• Anterior part of Talocalcaneonavicular
• Calcaneocuboid joint

Question 13

What kind of joints are metatarsophalangeal joints? What movements do they allow?

Answer 13

• They are condylar joints
• They are capable of flexion, extension, abduction, and adduction

Question 14

What kind of joints are interphalangeal joints? What movements do they allow?

Answer 14

• Synovial hinge joints
• Capable of flexion and extension

Question 15

List 3 reasons why it’s difficult to move the phalanges on the horizontal plane

Answer 15

1. Collateral ligaments in interphalangeal joints
2. Deep transverse ligaments at metatarsophalangeal joint
3. Lots of lateral articulation between metatarsals

Question 16

Describe the arrangement of plantar plates and sesamoid bones on the foot

Answer 16

• Plantar plates provide tunnels for tendons that plantarflex the foot
• Sesamoid bones are only present on the hallux, and exist within these tendons

(Plantar plates also increase articular surface for joints)