Lower Leg Anatomy

Question 1

State the bones of the knee joint and the movement

Answer 1

Formed by articulations between femur, tibia and patella
Modified hinge - rotation in flexion
Popliteus muscle ‘unscrews’ femur to begin flexion
Extension, and some lateral and medial rotation

Question 2

What type of cartilage lines the knee joint

Answer 2

Hyaline cartilage

Question 3

What are menisci

Answer 3

C-shaped fibrocartilagenous rings on medial and lateral surfaces of tibia
Load transmission, shock absorbency, instability, nutrition
Absorb tension - fills the gap inbetween bone surfaces
Deepens the articular surface making the joint more stable
Medial meniscus is fixed to tibial collateral ligament, so damage to ligament may damage meniscus

Question 4

Describe the patella ligament

Answer 4

A continuation of the quadriceps femoris tendon and inserts into tibial tuberosity

Question 5

Describe the role of the collateral ligaments in the knee

Answer 5

Medial and lateral collateral ligaments stabilize the knee and prevent medial or lateral rotation
Medial collateral ligament is a wide flat ligament that attaches to medial epicondyle of tibia
Lateral collateral ligament is thinner and rounder and attaches to lateral epicondyle of fibula

Question 6

Describe the role of the cruciate ligaments in the knee

Answer 6

ACL - attaches from the anterior intercyondyle region on the tibia and goes to the posterior femur
Prevents the tibia moving anteriorly
PCL - comes from the posterior inter condylar region of the tibia to the anterior femur
Prevents the tibia dislocating posteriorly, prevents femoral forward slide

Question 7

What is the role of bursa

Answer 7

Sac filled with synovial fluid

Acts to reduce ware and tear and improve mobility

Question 8

Describe the bursa around the knee joint

Answer 8

Suprapatella bursa: an extension of the knee synovial cavity, its located between the quadriceps femoris and the femur
Prepatella bursa: found between the patella and the skin
Infrapatella bursa: has deep and superficial parts
Deep lies between the tibia and the patella ligament
Superficial lies between the patella ligament and the skin
Semimembranosus bursa: between the knee, the semimembranosus muscle and the head of gastrocnemius

Question 9

State the anterior leg muscles and their innervation and major function

Answer 9

Tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius 
Deep peroneal (fibular) nerve
All dorsiflex foot

Question 10

Tibialis anterior - AFI

Answer 10

Strongest dorsiflexor of foot
Test by standing on heels
Attachments - originates from lateral surface of tibia and attaches to medial cuneiform at base of metatarsal I Actions - dorsiflexion and inversion of foot
Innervation - deep peroneal nerve

Question 11

Extensor digitorum longus - AFI

Answer 11

Attachments - originates from lateral condyle of tibia and medial surface of fibula
Converge into a tendon which travels to dorsal surface of foot, splits into 4 and inserts into a toe
Actions - extension of lateral four toes and dorsiflexion of foot
Innervation - deep peroneal nerve

Question 12

Extensor hallucis longus - AFI

Answer 12

Attachments - originates from medial surface of fibular shaft and attaches to base of distal phalanx of great toe
Action - extension of the great toe and dorsiflexion of the foot
Innervation - deep peroneal nerve

Question 13

Fibularis tertius - AFI

Answer 13

Attachment - originates with extensor digitorum longus from medial surface of fibula
At dorsal surface of foot, it diverges and attaches to metatarsal V
Actions - eversion and dorsiflexion of foot
Innervation - deep peroneal nerve

Question 14

What is the arrangement of the anterior muscles of the leg

Answer 14

Medial to lateral - tibialis anterior, extensor hallucis longus, extensor digitorum longus
THUD

Question 15

State the lateral leg muscles and their innervation and major function

Answer 15

Fibularis longus, fibularis brevis
Superficial peroneal nerve
All evert foot

Question 16

Fibularis longus - AFI

Answer 16

Attachments - originates form superior and lateral surface of fibula and lateral tibial condyle
Attaches to bones on medial side - medial cuneiform and base of metatarsal I
Actions - eversion and plantarflexion of foot
Supports lateral and transverse arches of foot
Innervation - superficial peroneal nerve

Question 17

Fibularis brevis - AFI

Answer 17

Attachments - originates from inferolateral surface of fibular shaft
Attaches to tubercle on metatarsal V
Actions - eversion of the foot
Innervation - superficial peroneal nerve

Question 18

State the superficial posterior leg muscles and their innervation and major function

Answer 18

Gastrocnemius, plantaris, soleus
Tibial nerve
All plantarflex foot

Question 19

Gastrocnemius - AFI

Answer 19

Attachments - lateral head originates from lateral femoral condyle
Medial head originates from medial femoral condyle
Inserts into calcaneal tendon
Actions - plantarflexes at ankle joint and flexion at knee
Innervation - tibial nerve

Question 20

Plantaris - AFI

Answer 20

Attachments - originates from lateral supracondylar line of femur
Actions - plantarflexes at ankle joint and flexion at knee
Innervation - tibial nerve

Question 21

Soleus - AFI

Answer 21

Attachments - originates from soleal line of tibia and proximal fibular area
Actions - plantarflexes the foot at ankle joint
Innervation - tibial nerve

Question 22

State the deep posterior leg muscles and their innervation and major function

Answer 22

Popliteus, tibialis posterior, flexor digitorum longus, flexor hallucis longus
Tibial nerve
All apart form popliteus plantarflex and invert foot

Question 23

Popliteus - AFI

Answer 23

Lies behind knee joint forms base of popliteal fossa
Attachments - originates from posterior surface of proximal tibia
Attaches to lateral condyle of femur and lateral meniscus of knee joint
Actions - laterally rotates the femur - unlocking the knee so flexion can occur
Innervation - tibial nerve

Question 24

Tibialis posterior - AFI

Answer 24

Attachments - originates from interosseous membrane between tibia and fibula
Travels posterior to medial malleolus and attaches to plantar surfaces of medial tarsal bones
Actions - inverts and plantarflexes foot, maintains medial arch of foot
Innervation - tibial nerve

Question 25

Flexor digitorum longus - AFI

Answer 25

Attachments - originates from medial surface of tibia and attaches to plantar surfaces of lateral 4 digits Actions - inverts and plantarflexes foot, flexes lateral 4 toes Innervation - tibial nerve

Question 26

Flexor hallucis longus - AFI

Answer 26

Attachments - originates from posterior surface of fibula and attaches to plantar surface of phalanx of great toe Actions - inverts and plantarflexes foot, flexes great toe Innervation - tibial nerve

Question 27

State the arrangement of deep posterior leg muscles near the medial malleolus

Answer 27

Tom Dick and a Very Nervous Harry From anterior to posterior - tibialis posterior, flexor digitorum longus, tibial artery, tibial vein, tibial nerve, flexor hallucis longus

Question 28

State the 7 tarsal bones

Answer 28

Talus, calcaneus, navicular, cuboid, 3 cuneiforms

Question 29

Describe the ligaments of the ankle joint

Answer 29

Medial ligament originate from medial malleolus and resist over-eversion of foot Include tibionavicular, tibiocalcaneal, and posterior tibiltabular Lateral ligaments originates from lateral malleolus and resist over-inversion of foot Anterior talofibular ligament spans between lateral malleolus and lateral aspect of talus Posterior talofibular ligament spans between lateral malleolus and posterior aspect of talus Calcaneofibular ligament spans between lateral malleolus and calcaneus

Question 30

Where is the subtalar joint

Answer 30

Articulation between the talus and calcaneus in the foot

Question 31

How is the subtalar joint stabilized

Answer 31

Subtalar joint enclosed by a joint capsule which is lined internally by synovial membrane and strengthened externally by a fibrous layer Supported by posterior, medial and lateral talocalcaneal ligament Interosseous talocalcaneal ligament binds talus and calcaneus together Lies within sinus tarsi - small cavity between talus and calcaneus to increase stability

Question 32

Explain how the medial arch of foot is formed and how it is supported

Answer 32

Formed by calcaneus, talus, navicular, three cuneiforms and first three metatarsal bones Supported by plantar fascia and plantar ligaments (bottom) Flexor hallucis longus ties bottom ends together Fibularis/peroneus longus suspends arch from above

Question 33

Explain the venous drainage system of the lower leg

Answer 33

Great saphenous vein ascends up medial side of leg and passes anterior to medial malleolus Drains into femoral vein Small saphenous vein ascends up posterior side of leg and passes posterior to lateral malleolus Drains into popliteal vein

Question 34

Explain the arterial system of the lower leg

Answer 34

Popliteal artery divides into anterior and posterior tibial artery Posterior tibial artery continues inferiorly and behind medial malleolus with tibial nerve Passes in-between flexor digitorum longus and flexor hallucis longus Anterior tibial artery travels in the interosseous space down into the foot

Question 35

What does the tibial nerve innervate and branch off to

Answer 35

Tibial nerve arises from popliteal fossa and gives branches to sural nerve Descends on posterior leg and innervates posterior muscles of leg Sural nerve runs in-between two heads of gastrocnemius

Question 36

Describe the sensory functions of the foot

Answer 36

Sural nerve provides sensation on lateral side of foot Superficial fibular (peroneal) nerve innervates skin on dorsum of foot Deep fibular (peroneal) nerve innervates skin between first and second toes Saphenous nerve runs with great saphenous vein anterior to medial malleolus Posterior tibial nerve gives sensation to sole of foot Lateral sural cutaneous nerve innervates skin over upper lateral leg

Question 37

What ankle ligament is most commonly injured

Answer 37

In an inversion injury, the anterior talofibular ligament is most likely to be injured, followed by calcaneofibular ligament and then posterior talofibular ligament