LL2 - Osteology of the leg, ankle & foot

Question 1

articulations forming the ankle joint?

Answer 1

trochlea of talus
medial malleolus & inferior surface of tibia
lateral malleolus of fibula

Question 2

what type of joint is the ankle joint? what movements does it allow?

Answer 2

synovial hinge joint - allows dorsiflexion & plantarflexion

Question 3

Why is the ankle joint more stable in dorsiflexion than plantarflexion?

Answer 3

anterior part of the talus is wider and fits snugly into the mortise formed by the tibia and fibula

posterior talus is narrower - makes plantarflexion less stable

Question 4

Which ligaments form the lateral ligament complex of the ankle? (3)

Answer 4

anterior talofibular ligament
- lateral malleolus to anterior talus

posterior talofibular ligament
- lateral malleolus to posterior talus

calcaneofibular ligament
- lateral malleolus to calcaneus

Question 5

what movement do the lateral ligaments of the ankle prevent?

Answer 5

ankle over-inversion

Question 6

Which lateral ligament is most commonly injured in an ankle sprain?

Answer 6

anterior talofibular ligament (ATFL) — due to inversion injuries

Question 7

why is the ankle joint sometimes described as a tenon & mortise joint?

Answer 7

tibia & fibula malleoli form the mortise/notch

talus trochlea slots in - allows for dorsiflexion and plantarflexion

Question 8

What are the four parts of the deltoid (medial) ligament?

Answer 8

anterior tibiotalar
posterior tibiotalar
tibiocalcaneal
tibionavicular

Question 9

what movement do the deltoid (medial) ligaments of the ankle prevent?

Answer 9

ankle over-eversion

Question 10

where does the spring ligament run to and from? what bone does it support?

Answer 10

runs from sustentaculum tali of calcaneus to navicular
- supports head of talus

Question 11

what does the spring (plantar calcaneonavicular) ligament support? (2)

Answer 11

supports head of talus
maintains medial longitudinal arch

Question 12

what arch of the foot does the spring ligament maintain?

Answer 12

medial longitudinal arch

Question 13

Which movement causes most ankle sprains: inversion or eversion? why?

Answer 13

ankle inversion - greater range of motion and weaker lateral ligaments

Question 14

what two ligaments help maintain the foot’s lateral longitudinal arch?

Answer 14

long plantar ligament
short plantar ligament

Question 15

what is the plantar aponeurosis? what does it help maintain?

Answer 15

plantar aponeurosis = thick fascia from calcaneus to toes

helps maintain both longitudinal arches & resists flattening during gait

Question 16

how does the anterior talofibular ligament (lateral ligament) protect the ankle? (2)

Answer 16

prevents ankle over-inversion during plantarflexion
prevents anterior displacement of talus

Question 17

how does the posterior talofibular ligament (lateral ligament) protect the ankle? (2)

Answer 17

prevents ankle over-inversion during dorsiflexion - stabilises movement
prevents posterior displacement of talus

Question 18

function of the interosseus membrane between the tibia and fibula (2)?

Answer 18

1. separates anterior & posterior leg muscle compartments
2. keeps tibia and fibula attached

Question 19

what nerve bifurcates at the neck of the fibula? into what branches?

Answer 19

common fibular nerve - branches into superficial & deep branches

Question 20

what part of the fibula contributes to the ankle joint?

Answer 20

lateral malleolus

Question 21

proximal tibiofibular joint - articulations? joint type?

Answer 21

articulations
- fibular head & lateral condyle of tibia

joint type
- synovial plane type (limited gliding movements)

Question 22

distal tibiofibular joint - articulations? joint type?

Answer 22

articulations
- fibular notch of distal tibia & distal fibula

joint type
- syndesmosis joint (ankle joint)

Question 23

hindfoot/heel bones of the foot?

Answer 23

talus
calcaneus

Question 24

where does the Achilles tendon insert on the calcaneous?

Answer 24

calcaneal tuberosity

Question 25

what muscle does the sustentaculum tali of the calcaneus have a groove for?

Answer 25

groove for flexor hallucis longus

Question 26

what bone does the sustentaculum tali of the calcaneus serve as a shelf for?

Answer 26

talus

Question 27

midfoot bones of the foot?

Answer 27

medial, intermediate & lateral cuneiforms cuboid navicular

Question 28

what muscle inserts on the navicular tuberosity?

Answer 28

tibialis posterior

Question 29

what muscle inserts on a tuberosity of the 5th metatarsal?

Answer 29

fibularis brevis

Question 30

Which bone of the hindfoot articulates with both the tibia and fibula?

Answer 30

talus

Question 31

A patient presents with weakness in foot eversion and pain over the lateral ankle. Imaging shows an avulsion at the base of the 5th metatarsal. What tendon is most likely involved? A) Tibialis posterior B) Fibularis longus C) Fibularis brevis D) Tibialis anterior E) Extensor digitorum brevis

Answer 31

C) Fibularis brevis - muscle inserts on 5th metatarsal tuberosity

Question 32

Where are the sesamoid bones of the foot located? Embedded under what tendon?

Answer 32

under head of 1st metatarsal (medial & lateral sesamoid bones) embedded in tendon of **flexor hallucis brevis**

Question 33

What tendon passes between the two sesamoid bones under the 1st metatarsal head?

Answer 33

flexor hallucis longus (sesamoid bones are *embedded* in flexor hallucis brevis)

Question 34

What structure attaches the tibia and fibula shafts and separates compartments?

Answer 34

interosseus membrane

Question 35

What is the function of the sustentaculum tali?

Answer 35

shelf for talus has a groove for the flexor hallucis longus

Question 36

What bone in the foot has a tuberosity for the fibularis brevis tendon?

Answer 36

5th metatarsal

Question 37

Which ligament inserts into the navicular and supports the medial longitudinal arch?

Answer 37

spring ligament (plantar calcaneonavicular ligament)

Question 38

A fracture at the neck of the fibula would most likely impair which of the following actions? A) Plantarflexion B) Knee flexion C) Toe extension D) Hip abduction E) Hip lateral rotation

Answer 38

**C) Toe extension** - common fibular nerve bifurcates at fibular neck; gives off superficial & deep branches. *damage to deep fibular nerve weakens toe flexors*

Question 39

During dissection, a tendon is seen running behind the medial malleolus and passing over a bony shelf on the calcaneus. What muscle does this tendon belong to? A) Tibialis posterior B) Flexor digitorum longus C) Flexor hallucis longus D) Peroneus longus E) Soleus

Answer 39

C) Flexor hallucis longus - groove on sustentaculum tali guides FHL to the hallux

Question 40

what attaches to the calcaneal tuberosity? what muscles insert here?

Answer 40

Achilles tendon - gastrocnemius, soleus & plantaris muscles insert

Question 41

what three joints does the calcaneus form?

Answer 41

1. subtalar joint = talus & anterior calcaneus 2. talocalcaneonavicular joint = talus, calcaneus, navicular 3. calcaneocuboid joint = calcaneus & cuboid

Question 42

what joint do the talocalcaneonavicular & calcaneocuboid joints form collectively?

Answer 42

transverse tarsal joint

Question 43

is the ankle joint more stable in plantarflexion or dorsiflexion? why?

Answer 43

**dorsiflexion** - wider anterior part of talus fits more snugly into TF mortise; posterior talus is more narrow & less stable

Question 44

what ligament of the ankle supports jumping?

Answer 44

**spring ligament** - talus goes up & down; spring ligament stabilises it

Question 45

Which ligament supports the head of the talus and the medial longitudinal arch?

Answer 45

spring ligament (plantar calcaneonavicular ligament)

Question 46

What ligament is most commonly torn in an inversion ankle sprain?

Answer 46

anterior talofibular ligament (ATFL)

Question 47

What condition results from tibialis posterior dysfunction?

Answer 47

Pes planus (collapse of medial arch)

Question 48

A 22-year-old basketball player inverts his ankle landing from a jump. He has swelling anterior to the lateral malleolus. What structure is most likely injured? A) Calcaneofibular ligament B) Spring ligament C) Anterior talofibular ligament D) Deltoid ligament E) Long plantar ligament

Answer 48

C) Anterior talofibular ligament

Question 49

Which ligament provides passive support to both the talus and the medial longitudinal arch? A) Long plantar ligament B) Spring ligament C) Short plantar ligament D) Deltoid ligament E) Plantar aponeurosis

Answer 49

B) Spring ligament

Question 50

The transverse arch of the foot is maintained dynamically by which pair of muscles? A) Tibialis posterior and fibularis longus B) Tibialis anterior and soleus C) Gastrocnemius and fibularis brevis D) Extensor digitorum longus and tibialis anterior E) Flexor hallucis longus and soleus

Answer 50

A) Tibialis posterior and fibularis longus

Question 51

A child presents with a collapsed medial longitudinal arch. Which muscle is most likely dysfunctional? A) Fibularis brevis B) Extensor hallucis longus C) Tibialis posterior D) Flexor hallucis brevis E) Tibialis anterior

Answer 51

C) Tibialis posterior

Question 52

In a posterior dislocation of the ankle joint, which ligament is most likely torn? A) Posterior tibiotalar (part of deltoid) B) Anterior talofibular ligament C) Tibiocalcaneal ligament D) Short plantar ligament E) Anterior tibiofibular ligament

Answer 52

A) Posterior tibiotalar (part of deltoid)

Question 53

Which structure plays the most significant passive role in supporting the medial longitudinal arch of the foot? A. Tibialis posterior B. Spring ligament C. Flexor digitorum longus D. Transverse metatarsal ligament E. Fibularis longus

Answer 53

B. Spring ligament

Question 54

Which muscle supports all three arches of the foot either directly or indirectly? A. Tibialis anterior B. Fibularis brevis C. Fibularis longus D. Flexor hallucis brevis E. Extensor digitorum longus

Answer 54

C. Fibularis longus - supports the medial, lateral, and transverse arches by crossing the sole and inserting medially

Question 55

Collapse of the medial longitudinal arch is most commonly associated with dysfunction of which muscle? A. Fibularis longus B. Flexor hallucis longus C. Tibialis posterior D. Tibialis anterior E. Gastrocnemius

Answer 55

C. Tibialis posterior - important in supporting medial arch

Question 56

The transverse arch is primarily maintained by which ligament? A. Long plantar ligament B. Spring ligament C. Transverse metatarsal ligament D. Short plantar ligament E. Plantar aponeurosis

Answer 56

C. Transverse metatarsal ligament

Question 57

Which combination of ligaments contributes to both medial and lateral longitudinal arch support? A. Spring ligament & transverse metatarsal ligament B. Short plantar & long plantar ligaments C. Plantar aponeurosis & spring ligament D. Long plantar ligament & fibularis brevis tendon E. Tibionavicular & tibiocalcaneal ligaments

Answer 57

B. Short plantar & long plantar ligaments

Question 58

What is pes planus (flatfoot)?

Answer 58

condition where the medial longitudinal arch collapses - flat appearance of the foot

Question 59

Name 3 contributing factors to acquired pes planus.

Answer 59

1. trauma to supporting ligaments/muscles 2. ligament laxity (hypermobility) 3. tibialis posterior dysfunction

Question 60

What role does the tibialis posterior play in pes planus?

Answer 60

dynamically supports the medial longitudinal arch—injury or weakening can lead to arch collapse

Question 61

What is pes cavus?

Answer 61

an exaggerated medial longitudinal arch

Question 62

common symptoms of pes cavus?

Answer 62

poor shock absorption increased risk of ankle instability pain in heels/foot pain

Question 63

What neurological disorder is associated with pes cavus?

Answer 63

Charcot-Marie-Tooth disease - causes muscle imbalance - weak muscle evertors overpowered by strong invertors = increases arch height

Question 64

how does muscle imbalance contribute to pes cavus?

Answer 64

strong invertors overpower weak evertors = exaggerates arch with dorsiflexion/plantarflexion imbalance

Question 65

Which ligaments may be weakened in pes planus?

Answer 65

spring ligament long & short plantar ligaments plantar aponeurosis