Leg

Question 1

Tarsal tunnel

Answer 1

Most structures pass between leg and foot through here, except anterior tibial artery, and ends of deep and superficial peroneal nerve which enter foot anterior to ankle

Question 2

Anterior compartment of leg

Answer 2

Dorsiflex ankle, extend toes and invert foot

Question 3

Posterior compartment of leg

Answer 3

Planterflex ankle, flex toes and invert foot

Question 4

lateral compartment of leg

Answer 4

evert foot

Question 5

Shaft of tibia

Answer 5

Borders - anterior, medial and interosseous
Surface - lateral, medial and posterior
Posterior surface marked by soleal line (an oblique line)
Has a groove for tibialis posterior tendon

Question 6

Soleal line

Answer 6

Descends from lateral to medial side where it merges with medial border

Question 7

Fibula

Answer 7

3 borders - anterior, posterior, interosseous
3 surfaces - lateral, posterior, medial
Has groove for peroneal longus and brevis muscles

Question 8

Posterior compartment of leg - muscles

Answer 8

Separated into 2 groups - superficial and deep, separated by a layer of deep fascia.
All are innervated by tibial nerve

Question 9

Superficial muscle in posterior compartment

Answer 9

gastrocnemius, soleus and plantaris
All insert into calcaneus and plantarflex the ankle joint
Gastroc and plantaris originate from distal end of femur hence can also flex the knee

Question 10

Gastrocnemius

Answer 10

Most superficial in posterior compartment of leg
Medial head - attached to posterior aspect of distal femur just behind adductor tubercle and above articular surface of medial condyle
Lateral head - from lateral femoral condyle
In lower leg, converge with deeper soleus muscle to form calcaneal tendon
Innervated by tibial nerve (S1, S2)

Question 11

Plantaris

Answer 11

Small muscle belly proximally and long thin tendon which descends through leg medially, between soleus and gastroc and joins calcaneal tendon
Origin - lateral supracondylar line of femur and oblique popliteal ligament of knee
Tibial nerve S1-S2

Question 12

Soleus

Answer 12

Origin - soleal line and medial border of tibia (originates from tibia, fibula and tendinous ligament)
Insertion - calcaneal tendon to posterior surface of calcaneus

Question 13

Deep posterior compartment of leg

Answer 13

popliteus, flexor hallucis longus, flexor digitorum longus and tibialis posterior
Popliteus acts on knee whilst the others on foot

Question 14

Popliteus

Answer 14

Smallest and most superior of deep posterior comp
Unlocks extended knee at initiation of flexion and stabilizes knee by resisting external rotation of tibia on femur
Origin - lateral femoral condyle
Insertion - posterior surface of tibia
Forms part of floor of popliteal fossa
Tibial nerve L4-S1

Question 15

Flexor hallucis longus

Answer 15

Most lateral side in posterior comp
Origin - lower 2/3 of posterior surface of fibula and adjacent interosseous membrane
Insertion - plantar surface of great toe on medial side of foot
Tibial nerve S2-S3
Flexes great toe

Question 16

Flexor digitorum longus

Answer 16

Origin - medial side of posterior surface of tibia
Insertion - plantar surface of base of distal phalanges of lateral 4 toes
Tibial nerve S2-S3
Flexes lateral 4 toes

Forms tendon which crosses posterior (superficial) to tendon of tibialis posterior near ankle joint. Crosses inferior (superficial) to FHL to reach medial side of foot then divides into 4 tendons

Question 17

Tibialis posterior

Answer 17

Origin - posterior surface of interosseous membrane and adjacent regions of tibia and fibula
Insertion - tuberosity of navicular and adjacent region of medial cuneiform
Lies in between and overlapped by FDL and FHL
Tendon of TP lies medial to tendon of FDL in groove on posterior surface of medial malleolus.
Inverts and plantarflex foot and supports medial arch while walking
Tibial nerve L4-L5

Question 18

popliteal artery

Answer 18

passes into posterior compartment between gastroc (superficial) and popliteus (deep)
It passes under tendinous arch formed between fibular and tibial heads of soleus as it continues inferiorly
Enters deep compartment and divides into anterior tibial and posterior tibial artery.
Branches into 2 large sural arteries in popliteal fossa to supply gastroc, plantaris and soleus.

Question 19

anterior tibial artery

Answer 19

passes forward through aperture in upper part of interosseous membrane and supplies anterior compartment. Continues inferiorly onto dorsal aspect of foot

Question 20

posterior tibial artery

Answer 20

supplies posterior and lateral compartment and continues to sole of foot
Descends through deep posterior compartment on superficial surfaces of TP and FDL, passes through tarsal tunnel behind medial malleolus and into sole of foot

Question 21

Branches of posterior tibial artery

Answer 21

Circumflex peroneal artery - passes laterally through soleus and around neck of fibula to connect to anastomotic network around knee
Peroneal artery - parallels course of tibial artery but runs in lateral compartment

Question 22

Tibial nerve

Answer 22

passes under tendinous arch formed between fibular and tibial heads of soleus, goes through deep posterior compartment with posterior tibial vessels

enters ankle through tarsal tunnel behind medial malleolus and supply most intrinsic muscles and skin

Question 23

branch of tibial nerve in leg

Answer 23

Branches that supply all muscles in posterior leg

Two cutaneous - sural nerve and medial calcaneal nerve

Question 24

Sural nerve

Answer 24

originates high in leg between two heads of gastrocnemius. Descends superficial to belly of gastroc and penetrates deep fascia in middle of leg where it is joined by sural communicating branch from common peroneal nerve.
Passes down leg around lateral malleolus into the foot
Supplies lower posterolateral surface

Question 25

Medial calcaneal nerve

Answer 25

Descends on medial side of heel | Innervates skin on medial surface and sole of heel

Question 26

Muscle in lateral compartment

Answer 26

Peroneus brevis and longus | Both innervated by superficial peroneal nerve

Question 27

Peroneus longus

Answer 27

Arises in lateral compartment of leg but its tendon crosses under foot to attach to bones on medial side Origin: upper lateral surface of fibula Attachment: undersurface of distal end of medial cuneiform and base of metatarsal I Distally, tendon of peroneus longus passes posterior to lateral malleolus

Question 28

Route of common peroneal nerve

Answer 28

From popliteal fossa, follows medial margin of biceps femoris over lateral head of gastroc and toward tibula Here branches into 2 cutaneous branches - sural communicating (combines with sural nerve) and lateral sural cutaneous nerve (upper lateral leg) Common peroneal nerve passes anteriorly around fibular neck between attachment of peroneus longus to fibular head and shaft

Question 29

Peroneus brevis

Answer 29

deep to peroneus longus Origin: lateral 2/3rds of lateral surface of fibular shaft Insertion: lateral tubercle at bae of metatarsal V Tendon of peroneus brevis passes behind lateral malleolus

Question 30

Common peroneal nerve

Answer 30

Branches into superficial peroneal nerve and deep peroneal nerve

Question 31

Superficial peroneal nerve

Answer 31

Descends in lateral compartment deep to peroneus longus to innervate peroneus longus and brevis Enters foot and divides into medial and lateral branches which supply dorsal areas of foot and toes except - web space between great and second toe (deep peroneal nerve) - lateral side of little toe (sural nerve)

Question 32

Deep peroneal nerve

Answer 32

passes anteromedially through intermuscular septum into anterior compartment of leg which it supplies

Question 33

Muscles in anterior compartment

Answer 33

tibialis anterior, EHL, EDL and peroneus tertius | Deep peroneal nerve

Question 34

Tibialis anterior

Answer 34

most anterior and medial of the muscles in anterior compartment Origin: lateral surface of tibia Insertion: medial cuneiform and metatarsal I Dorsiflex ankle, inverts foot and supports medial arch during walking

Question 35

EHL

Answer 35

lies next to and partly overlapped by tibialis anterior. tendon appears between tibialis anterior (medial) and EDL (lateral) in lower half of leg and into foot. Inserts on upper surface of base of distal phalanx.

Question 36

EDL

Answer 36

Most posterior and lateral of muscles in anterior compartment. Origin: lateral to and above origin of EHL

Question 37

Peroneus tertius

Answer 37

Originates from below origin of EDL. Tendon descends into foot with tendon of EDL. On dorsal aspect of foot, deviates laterally to insert onto base of metatarsal V Assists in dorsiflexion and eversion of foot.

Question 38

Anterior tibial artery

Answer 38

Distal leg, lies in between tendons of tibialis anterior and EHL. Leaves leg by passing anteriorly to distal end of tibia and continues as dorsalis pedis Distally gives rise to anteiror medial malleolar and anterior lateral malleolar artery

Question 39

Deep peroneal nerve

Answer 39

Originates in lateral compartment, passes anteromedially through intermuscular septum and then passes deep to EDL. At anterior interosseous membrane meets and descends with anterior tibial artery Inervates all muscles in anterior compartment, EDB, first 2 dorsal interossei and skin between great and second toes