Leg and Ankle Anatomy - Unit 6

Question-and-answer flashcards covering tibia, fibula, tibiofibular joints, talus, ankle joint structure, and ligament support.

What is the main function of the tibia?

It is the primary weight-bearing bone that transfers load from the femur to the talus.

What are the three borders of the tibia?

Anterior, medial, and interosseous borders (the latter is sharp for interosseous membrane attachment).

The soleal line of the tibia marks which muscular borders?

It marks the inferior border of the popliteus and the superior border of the soleus.

What is the function of the medial malleolus?

It forms part of the ankle joint and articulates with the talus.

Where is the fibular notch located and what is its role?

It is on the lateral distal tibia and holds the distal fibula in place.

Is the fibula a weight-bearing bone?

No, it serves primarily as a muscle-attachment site.

Which structures attach to the head of the fibula?

The biceps femoris tendon and the fibular (lateral) collateral ligament.

What action do the eight distal fibular muscles collectively perform?

They pull the fibula downward.

Which tendons use the grooves on the lateral malleolus as a pulley system?

The tendons of fibularis (peroneus) longus and fibularis brevis.

What role does the fibula play at the ankle joint?

It provides lateral stability through its articulation with the talus.

What type of joint is the proximal tibiofibular joint?

A plane synovial joint.

What motions occur at the proximal tibiofibular joint?

Small gliding motions in anterior-posterior and superior-inferior directions.

What type of joint is the distal tibiofibular joint?

A syndesmosis (fibrous joint).

Which ligament is the strongest stabilizer of the distal tibiofibular joint?

The interosseous tibiofibular ligament.

What is the inferior transverse ligament?

A distal extension of the posterior tibiofibular ligament.

Where is the talus located?

In the hindfoot; it is one of the seven tarsal bones.

Name the three joints in which the talus participates.

The talocrural, subtalar, and transverse tarsal joints.

What is unique about the trochlea of the talus?

It is the weight-bearing surface of the talus and is wider anteriorly than posteriorly.

With which bone does the head of the talus articulate?

The navicular bone.

Where do the deltoid and posterior talofibular ligaments attach on the talus?

On its posterior medial and lateral tubercles.

What type of joint is the talocrural (ankle) joint?

A hinge-type synovial joint.

Which bones form the ankle mortise?

The distal tibia and distal fibula create a socket (mortise) for the talus.

Why does the ankle mortise allow slight movement during dorsiflexion?

To accommodate the wider anterior portion of the talar trochlea.

What are the three lateral ligaments of the ankle?

Anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL).

During which movements is the anterior talofibular ligament (ATFL) most taut?

Plantarflexion and inversion.

What motion does the calcaneofibular ligament (CFL) limit?

Inversion of the subtalar joint.

What is the primary stabilizing role of the posterior talofibular ligament (PTFL)?

It stabilizes the talus during dorsiflexion and limits abduction and external rotation.

What is the medial ligament complex of the ankle called?

The deltoid ligament.

Which motions does the deltoid ligament limit?

Eversion and rotary motions of the talus.

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

The anterior talofibular ligament (ATFL).

Which structure helps the fibula resist downward pull from attached muscles?

The combined attachment of the biceps femoris tendon and the fibular collateral ligament.

What analogy is often used to describe how the talus fits into the ankle mortise?

Like a table leg (tenon) fitting into a tabletop (mortise).