Biomechanics of the Foot and Ankle

Question 1

What bones make up the shank?

Answer 1

Tibia and fibula.

Question 2

What movement does the shank perform with rearfoot pronation?

Answer 2

Medial rotation.

Question 3

What joint is formed by the talus and the mortise?

Answer 3

Talocrural joint.

Question 4

What is the primary function of the talocrural joint?

Answer 4

Dorsiflexion and plantarflexion.

Question 5

What shape is the trochlear surface of the talus?

Answer 5

Wedge-shaped and thicker in the front

Question 6

When is the talocrural joint most stable?

Answer 6

In dorsiflexion.

Question 7

What bones articulate in the subtalar joint?

Answer 7

Talus and calcaneus.

Question 8

What is the functional role of the subtalar joint?

Answer 8

Transmits forces between the foot and tibia; allows mobility and stability.

Question 9

What joints make up the midtarsal joint?

Answer 9

Talonavicular and calcaneocuboid.

Question 10

What joints are involved in the tarsometatarsal joint (Lisfranc)?

Answer 10

Cuneiforms with MT 1–3 and cuboid with MT 4–5.

Question 11

What ligament transfers WB forces to the fibula?

Answer 11

Interosseous ligament.

Question 12

Which ligaments prevent fibula displacement?

Answer 12

Tibiofibular ligaments.

Question 13

What is the main restraint against eversion?

Answer 13

Deltoid ligament.

Question 14

What ligaments restrain inversion?

Answer 14

Anterior/posterior talofibular and calcaneofibular ligaments.

Question 15

What is the function of the 1st metatarsophalangeal joint?

Answer 15

Transmits forces during walking and jumping.

Question 16

What percentage of body weight is transmitted through the 1st MTP during jumping?

Answer 16

Up to 800%.

Question 17

What is the function of the plantar fascia?

Answer 17

Maintains longitudinal arch and controls pronation.

Question 18

When is plantar fascia tension highest?

Answer 18

Between initial contact and loading response.

Question 19

What are potential causes of heel pain?

Answer 19

Subcutaneous bursa, retrocalcaneal bursa, and calcaneal fat pad.

Question 20

What is the second leading source of heel pain?

Answer 20

Calcaneal fat pad.

Question 21

What is the primary function of anterior tibialis?

Answer 21

Dorsiflexion and inversion.

Question 22

What muscle extends the great toe?

Answer 22

Extensor hallucis longus.

Question 23

What muscle extends digits 2–5?

Answer 23

Extensor digitorum longus.

Question 24

What is the role of peroneus tertius?

Answer 24

Assists in dorsiflexion and eversion.

Question 25

What is the function of the extensor retinaculum?

Answer 25

Prevents tendon subluxation and maintains line of force.

Question 26

What muscles make up the superficial posterior compartment?

Answer 26

Gastroc, soleus, and plantaris.

Question 27

What nerve innervates the posterior compartment?

Answer 27

Tibial nerve.

Question 28

What does the posterior tibialis muscle do?

Answer 28

Plantarflexes, everts, and stabilizes the arch.

Question 29

What is the Windlass mechanism?

Answer 29

Passive tension in plantar fascia during toe extension creates a rigid lever.

Question 30

What are the deep muscles in the posterior compartment?

Answer 30

Tibialis posterior, FDL, FHL.

Question 31

What is the flexor retinaculum?

Answer 31

A structure from the medial malleolus to calcaneus that forms the tarsal tunnel.

Question 32

What runs through the tarsal tunnel?

Answer 32

Tibialis posterior, FDL, FHL, tibial nerve, artery, and vein.

Question 33

What muscles are in the lateral compartment?

Answer 33

Fibularis longus and brevis.

Question 34

What is the primary function of fibularis brevis?

Answer 34

Eversion and resisting inversion during gait.

Question 35

What is the distal attachment of fibularis longus?

Answer 35

Medial cuneiform and base of 1st MT.

Question 36

What foot muscles are innervated by the medial plantar nerve?

Answer 36

Abd hallucis, FDB, FHB, and 1st lumbrical.

Question 37

What muscles does the lateral plantar nerve innervate?

Answer 37

Quadratus plantae, FDM, add hallucis, lateral lumbricals, interossei, abductor digiti minimi.

Question 38

What is Morton’s neuroma?

Answer 38

A nerve entrapment between metatarsal heads causing forefoot pain.

Question 39

What does the tibial nerve supply?

Answer 39

Motor and sensory innervation to the posterior leg and foot.

Question 40

What muscles are innervated by the superficial fibular nerve?

Answer 40

Fibularis longus and brevis.

Question 41

What muscles are innervated by the deep fibular nerve?

Answer 41

Anterior tibialis, EHL, EDL, and dorsal intrinsics.

Question 42

What does the sural nerve innervate?

Answer 42

Lateral aspect of the foot.

Question 43

What condition is caused by tibial nerve compression in the tarsal tunnel?

Answer 43

Tarsal tunnel syndrome.

Question 44

What mechanism helps create a rigid lever during push-off in gait?

Answer 44

Windlass mechanism.

Question 45

What muscle controls pronation eccentrically?

Answer 45

Posterior tibialis.

Question 46

What kind of collagen is found in plantar fascia?

Answer 46

Type I collagen.

Question 47

Which joint acts as the bridge between foot and ankle?

Answer 47

Subtalar joint.

Question 48

What is another name for the midtarsal joint?

Answer 48

Chopart joint.

Question 49

What is another name for the tarsometatarsal joint?

Answer 49

Lisfranc joint.

Question 50

What muscle stabilizes the talocrural joint in CKC?

Answer 50

Anterior tibialis.