L21_The leg and Foot (2)

Question 1

Anterior compartment of the leg

Describe the Tibialis Anterior (origin, insertion, function, innervation)

Answer 1

Origin: Lateral tibial condyle and shaft of tibia

Insertion: Medial cuneiform

Function: Dorsiflexion and inversion of the foot

Innervation: Deep fibular (peroneal) nerve (L4-L5)

Question 2

Anterior compartment of the leg

Describe the Extensor Digitorum Longus (origin, insertion, function, innervation)

Answer 2

Origin: Lateral tibial condyle, head fibula and the anterior interosseus membrane

Insertion: dorsum of lateral 4 toes via extensor expansions (middle and distal phalanges)

Functions: Extension of the toes, dorsiflexion of the foot

Innervation: Deep fibular (peroneal) nerve (L5-S1)

Question 3

Anterior compartment of the leg

Describe the Fibularis (Peroneus) Tertius (origin, insertion, function, innervation)

Answer 3

Origin: fibula

Insertion: Dorsum of 5th metatarsal shaft

Function: Dorsiflexion and eversion of the foot

Innervation: deep fibular (peroneal) nerve (L5-S1)

Question 4

Anterior compartment of the leg

Describe the Extensor Hallucis Longus (origin, insertion, function, innervation)

Answer 4

Origin: Anterior fibula and interosseus membrane

Insertion: Base of the distal phalanx of hallux

Function: extension of hallux, dorsiflexion of the foot

Innervation: deep fibular (peroneal) nerve (L5, S1)

Question 5

Lateral compartment of the leg

Describe the Fibularis (Peroneus) Longus (origin, insertion, function, innervation)

Answer 5

Origin: Head and proximal lateral fibula

Insertion: Medial cuneiform and base of 1st metatarsal (plantar surface)

Function: Eversion and plantar flexion of the foot. Supports lateral longitudinal transverse arch

Innervation: Superficial fibular (peroneal) nerve

Question 6

Lateral compartment of the leg

Describe the Fibularis (Peroneus) Brevis (origin, insertion, function, innervation)

Answer 6

Origin: Distal 2/3 of lateral fibula

Insertion: Metatarsal V

Function: Eversion and plantar flexion of the foot

Innervation: Superficial fibular (peroneal) nerve (L5-S1-2)

Question 7

Superficial Posterior compartment of the leg

Describe the Gastrocnemius (origin, insertion, function, innervation)

Answer 7

Origin:

Medial head -> medial femoral condyle

Lateral head -> lateral femoral condyle

Insertion: Dorsum of the calcaneus via calcaneal tendon

Function: Flexes the leg at the knee, plantarflexion of the foot at the ankle

Innervation: Tibial nerve (S1,S2)

Question 8

Superficial Posterior compartment of the leg

Describe the Soleus (origin, insertion, function, innervation)

Answer 8

Origin: Soleal line, head of the fibula

Insertion: dorsum of the calcaneus via calcaneal tendon

Function: Plantarflexion of the foot at the ankle

Innervation: tibial nerve (S1,S2)

Question 9

Superficial Posterior compartment of the leg

Describe the Plantaris (origin, insertion, function, innervation)

Answer 9

Origin: Lateral supracondylar line

Insertion: Posterior Calcaneus

Function: weak knee flexion and weak plantar flexion

Innervation: Tibial nerve (S1,S2)

Question 10

Deep Posterior compartment of the leg

Describe the Flexor Hallucis Longus (origin, insertion, function, innervation)

Answer 10

Origin: distal 2/3 of the posterior fibula

Insertion: Base of the distal phalanx of hallux

Function: plantarflexion of the foot at the ankle, flexion of the hallux, inversion of the foot

Innervation: Tibial nerve (S2,S3)

Question 11

Deep Posterior compartment of the leg

Describe the Flexor Digitorum Longus (origin, insertion, function, innervation)

Answer 11

Origin: Posterior Tibia distal to soleal line

Insertion: Base of the distal phalanx of lateral 4 toes

Function: plantar flexion, toe flexion (lateral 4 toes), inversion of the foot

Innervation: Tibial nerve (L4-L5)

Question 12

Deep Posterior compartment of the leg

Describe the Tibialis Posterior (origin, insertion, function, innervation)

Answer 12

Origin: Posterior tibia, fibula and interosseous membrane

Insertion: Navicular, cuboid, cuneiforms, sustentaculum tali of calcaneus and bases of metatarsals 2-4

Function: Plantar-flexion and inversion of the foot (supports the medial longitudinal arch)

Innervation: Tibial nerve (L4-L5)

Question 13

Describe the neurovascular supply to the leg (NERVE)

Answer 13

Common fibular nerve

• > deep fibular nerve (motor innervation to the ANTERIOR compartment of the leg - Sensory innervation to the space between digits I - II)
• > Superficial fibular nerve (motor innervation to the LATERAL compartment of the leg - Sensory innervation to the lateral side of the leg and the dorsum of the foot))

Tibial nerve (motor innervation to the POSTERIOR compartment of the leg)

• > Medial plantar nerve
• > Lateral plantar nerve

Question 14

Describe the neurovascular supply to the leg (ARTERY)

Answer 14

Popliteal artery splits into anterior and posterior tibial artery

• > Anterior tibial artery: Pierces through the interosseous membrane and gives blood supply to the ANTERIOR compartment of the leg
• > Posterior tibial artery: Gives blood supply to the POSTERIOR compartment of the leg

the posterior tibial artery gives off a branch called the fibular artery

-> Fibular artery: Gives blood supply to the LATERAL compartment of the leg

Question 15

Discuss the tarsal tunnel (contents in order)

Answer 15

From anterior to posterior

Tom: Tibialis Posterior

Dick: Flexor Digitorum Longus

And: Posterior tibial artery

Very: Posterior tibial vein

Nervous: Tibial nerve

Harry: Flexor Hallucis Longus

Question 16

Explain the function of the synovial sheaths around the tendons of the leg

Answer 16

Need more info…

When the tendon of the flexor hallucis longus muscle is going to get pulled further and wrap around the sustentaculum tali of calcaneus in order to lengthen the pully system of this muscle and get much more of a stringer flexion of the first digit