Sem 2 - M - Plantar surface of foot - deep fascia, compartments, 4 layers, cutaneous, plantar arteries/nerves

Question 1

The foot can be divided into the hindfoot, midfoot and forefoot Which bones are involved in each of these divisions of the foot?

Answer 1

• Hindfoot - talus and calcaenus
• Midfoot - navicular, cuneiforms (medial, intermediate and lateral) and cuboid
• Forefoot - metatarsals and phalnges (2 in big toes, 3 in the four lateral toes)

Question 2

Due to the arrangement of the bones, they way we look at the foot from above differs from the shape of the bones below What aspect of the talus and cuneiforms can be seen from below? What is special about the head of the 1st metatarsal?

Answer 2

• Can only see the head of the talus when looking at the foot from below
• Can see the medial cuneiform clearly however only a small amount of the intermediate and lateral cuneiforms are visible
• Distally, the tendon of the flexor hallucis brevis splits and within each tendon is a sesamoid bone at the head of the 1st metatarsal - this provides a tunnel for the FHL tendon to travel through

Question 3

Immediately after removing the skin of the foot is the deep fascia of the foot What are the different aspects of the deep fascia of the plantar surface of the foot?

Answer 3

The deep fascia of the foot is very thick It is thickest at its central portion - known as the plantar aponeurosis and has a weaker medial and lateral portion

Question 4

As said, the plantar aponeurosis is formed as the central portion of the deep fascia What are the plantar aponeurosis attachments?

Answer 4

Plantar aponeurosis attaches proximally to the calcaneous and distally divides into 5 bands which are continous with the fibrous sheaths of the digits

Question 5

Bands of deep fascia go into the sole of the foot dividing it into medial, lateral and central compartments What are these deep fascial bands known as?

Answer 5

Deep fascial bands dividing the sole of the foot into compartment is known as the vertical intermuscular septae

Question 6

What are the two muscles of the dorsum of the foot? State their attachments, nerve supply and function

Answer 6

Origin - superior surface of calcaenus and inferior extensor retinaculum

• EDB - to the long extensor tendons of toes 2-4 Extends the digits 2-4
• EHB - to the base of the proximal phalnyx of hallux Extends the big toe

Both innervated by deep peroneal nerve (L5, S1)

Question 7

The muscles of the plantar aspect of the foot can be divided into medial, central and lateral compartments by fascial arrangement as stated Name the muscles in each comparmtnet?

Answer 7

Interossie throughout

• Lateral - abductor digiti minimi and flexor digiti minimi brevis
• Central - flexor digitorum brevis, muscles associated with the flexor digitorum longus tendon (quadratus plantae and lumbricals) and adductor hallucis
• Medial - abductor hallucis and flexor hallucis brevis

Question 8

The muscles of the plantar aspect of the foot can be divided into 4 different layers Which muscles are in each layer?

Answer 8

• * Layer 1 - Abductor hallucis, flexor digitorum brevis, abductor digiti minimi (one from each compartment)
• * Layer 2 - Muscles associated with the tendon of flexor digitorum longus (quadratus plantae and lumbricals) and tendon of flexor hallucis longus
• * Layer 3 - flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis (one from each compartment)
• * Layer 4 - Plantar and dorsal interossie (tendons of peroneus longus and tibialis posterior)

Question 9

State the attachment of abductor hallucis and its function

Answer 9

Attaches from the medial tubercle of calcaneus and the flexor retinaculum and inserts into the medial base of the proximal phalnyx Abductor hallucis abducts the big toe

Question 10

State the attachments and function of the flexor digitorum brevis

Answer 10

Flexor digitorum brevis attaches from the medial tubercle of the calcaenous to either side of the middle phalnges of the lateral 4 toes Function - flexion of the lateral four digits at the PIP joints and flexion of MTP joint

Question 11

State the attachments and function of abductor digiti minimi

Answer 11

Abductor digiti minimi attaches from the medial and lateral tubercle of the calcaneous to the lateral aspect of the base of the proximal phalnyx of the little toe Function - abduction of little toe

Question 12

State the attachments of the muscles of layer 1 from the foot

Answer 12

• Abductor hallucis - medial tubercle of calcaneus and flexor retinaculum to the medial base of proximal phalnyx of the big toe
• Flexor digitorum brevis - medial tubercle of calcaneus to the either side of the middle phalnyx of lateral 4 digitis
• Abductor digiti minimi - medial & lateral tubercle of calcaneous to the lateral base of proximal phalnyx of little toe

Question 13

Which muscles are in layer 2 of the foot and which lies directly deep to flexor digitorum brevis?

Answer 13

Long flexor tendons to the toes from flexor digitorum longus and flexor hallucis longus Quaratus plantae and lumbricals

Flexor digitorum longus tendon lies directly beneath the flexor hallucis brevis

Question 14

What is the attachment of the lumbricals and its function?

Answer 14

Lumbricals - attach from the tendons of the FDL and cross over the MTP joint on the plantar surface of the foot before wrapping around to attach onto the medial side of the dorsal expansion of the digits

Function - flexes the MTP joints and extends the IP joints

Question 15

What is the other name for quadratus plantae? What are its attachments and what is its function?

Answer 15

QP (flexor accessorius)- originates from the medial and lateral surfaces of the calcaneus to insert onto the lateral side of the FDL tendon

Function - aids flexion of lateral four digits whilst counteracting the medial oblique pull of the FDL due to its attachment on the lateral aspect of the tendon

Question 16

State the attachments of the lumbricals and quadratus plantae again

Answer 16

Lumbricals - tendons of FDL then travel across the plantar surface of MTP before wrapping around the digit to insert onto the medial side of the dorsal expansion of the digits

Quadratus plantae (flexor accessorius) - medial and lateral surface of the calcaneus to the lateral aspect of the FDL tendon

Question 17

Why is the flexor digitorum brevis tendon split distally?

Answer 17

The flexor digitorum brevis tendon splits distally to attach to either side of the middle phalnyx of the lateral 4 toes to allow the flexor digitorum longus tendon to travel between the split and attach onto the distal phalnyx of the lateral 4 toes

Question 18

What are the muscles of the third layer of the plantar aspect of the foot?

Answer 18

Flexor hallucis brevis Adductor hallucis Flexor digiti minimi brevis

Question 19

What are the attachments of the flexor hallucis brevis and what is its function?

Answer 19

Flexor hallucis brevis

• Attaches from the cuboid and lateral cuneiform and inserts at both sides of the base of the proximal phalnyx of the big toe
• Function - Flexion of the MTP joint

Question 20

What are the attachments and function of the adductor hallucis?

Answer 20

• Transverse head - originates at the plantar ligament of the MTP joints
• Oblique head - originates at the base of metatarsals 2-4
• Both heads insert at the lateral side of the base of the proximal phalnyx of the big toe

Function - Adducts the big toe

Question 21

What are the attachments and function of the flexor digiti minimi?

Answer 21

Attachments - base of 5th metatarsal to base of proximal phalnyx of 5th digit

Flexes the MTP joint of little toe

Question 22

State the attachments of the third layer muscles of the sole of the foot

Answer 22

• Flexor hallucis brevis - cuboid and lateral cuneiform to both sides of the base of the proximal phalnyx of the big toe
• Adductor hallucis - transverse head from the plantar ligament of the MTP joints, oblique head from base of metatarsal 2-4 and inserts onto lateral aspect of base of proximal phalnyx of big toe
• Flexor digiti minimi - base of 5th metatarsal to base of proximal phlanyx of little toe

Question 23

When we walk, we put pressure on the tendons crossing the MTP joints therefore preventing these muscle tendons acting distally We need the tendons of the flexor hallucis longus to flex the big toe to allow for pushing off when walking What prevents this tendon from being compressed?

Answer 23

There is a sesamoid bone in each of the tendons of the flexor hallucis brevis which therefore creates a tunnel for the flexor hallucis longus tendon to pass through and not become compressed when walking

Question 24

What muscles exist in layer 4 of the plantar foot?

Answer 24

Plantar and dorsal interossei as well as the tendons of tibialis posterior and peroneus longus

Question 25

What is axial digit of the hand and foot?

How many plantar and dorsal interossie are there and which are uni/bipennate?

Answer 25

The axial digit of the hand is the middle finger

The axial digit of the foot is the 2nd digit

There are 3 plantar interosse all unipennate

There are 4 dorsal interossei all bipennate

Question 26

What are the attachments of the plantar interossei and what is their function?

Answer 26

Plantar interossei attach from the bases and medial sides of metatarsals 3-5 and insert onto the medial side of the proximal phalnyx of the 3rd-5th digit

• Plantar interossie ADuct

Dont need a plantar interossie for 1st digit as have adductor hallucis or 2nd digit as index finger is the axial digit

Question 27

What is the attachment and function of the dorsal interossei?

Answer 27

Attach from adjacent sides of metatarsals 1-5

• 1st muscle inserts to the medial side of the proximal phalnyx of 2nd digit
• 2-4 muscles insert to the lateral side of proximal phalnyx of digits 2-4
• Dorsal interossei ABduct

1st and 5th digit have abductor hallucis and abductor digiti minimi respectively

Question 28

Re-state the attachments of the plantar and dorsal interossei

Answer 28

Plantar interossei - ADduct

• Bases and medial aspect of metatarsals 3-5 (unipennate) to the medial side of proximal phalanyx of digits 3-5

Dorsal interossei - ABduct

• Adjacent sides of metatarsals 1-5
• 1st muscle to medial side of proximal phalnyx of 2nd digit
• Muscles 2-4 to lateral side of proximal phalnyx of digits 2-4

Question 29

What were the two tendons in the 4th layer of the plantar foot?

Answer 29

This would be the tibialis posterior tendon and the peroneus longus tendon

Question 30

What nerve do the branches to the muscles of the sole of the foot come from?

What muscles does this nerve enter the sole of the foot deep to?

Answer 30

Nerve branches supplying the sole of the foot come from the tibial nerve

Tibial nerve passes posterior to the medial malleolus of the foot deep to the flexor retinaculum and then into the sole of the foot deep to the abductor hallucis where it will split to form the medial and lateral plantar nerves

Question 31

What do the medial and lateral plantar nerves run deep to/in between?

Answer 31

• Medial plantar nerve runs between the abductor hallucis and flexor digitorum brevis
• Lateral plantar nerve will run between layers 1 and 2 where it will divide into superficial branches Deep branch runs between layers 3 and 4 of

Question 32

State the nerve supply and roots to the muscles of the sole of the foot

Answer 32

Nerve roots to every muscle is S2,3

Medial plantar nerve

• Abductor hallucis
• Flexor digitorum brevis
• 1st lumbrical
• Flexor hallucis brevis

Lateral plantar nerve - Supplies all the other intrinsic muscles of foot

Question 33

State what the nerve name in each box is

Answer 33

• Red - saphenous nerve
• Black - superficial peroneal nerve
• Green- deep peroneal nerve
• Blue - dorsal lateral cutaenous nerve of the foot - sural nerve branch
• Brown - medial plantar nerve
• Pink - lateral plantar nerve
• Yellow - calcaneal branches from tibial nerve

Question 34

Where do the plantar arteries arise from?

Answer 34

The posterior tibial artery passes deep to the flexor retinaculum of the foot posterior to the medial malleolus and then enters the sole of the foot deep to abductor hallucis before dividing into medial and lateral plantar arteries

Question 35

What does the medial plantar artery supply and contribute to?

Answer 35

Medial plantar artery supplies muscles of hallux and overlying skin

Occasionally will continue in some individuals to form the superficial plantar arch around the head of the 1st metatarsal

Question 36

Where does the lateral pantar artery run and what does it give rise to?

Answer 36

Lateral plantar artery runs with lateral plantar nerve and is initially between layers 1 and 2 of the foot

• It will give rise to the deep plantar arch of the foot between layers 3 and 4 which will anastamose with the deep plantar artery from the dorsalis pedis artery

Question 37

In the dorsum of the foot, the arcuate artery will run across the metatarsals to anastamose with the lateral tarsal artery Whilst the arcuate artery runs here, it will give metatarsal and digital artery branches What gives the metatarsal and digital artery branches in the sole of the foot?

Answer 37

The deep plantar arch from the deep branch of the lateral plantar artery will give metatarsal and digital arteries in the sole of the foot