Foot

Question 1

Describe the bones of the foot

Answer 1

Tarsal Bones (7)
Talus
Calcaneus
Navicular
Cuneiforms (medial, intermediate, lateral)

Metatarsal Bones (5)
1st (medial, big toe) through 5th
Each metatarsal consists of base proximally, shaft, and head distally
5th metatarsal has styloid tuberosity projecting posterolaterally (fibularis longus tendon)

Phalanges (14)
Big toe: proximal & distal only
Other toes: proximal, intermediate & distal
Each phalanx consists of base proximally, shaft, and head distally

Question 2

Describe the cutaneous nerves of the leg/foot.

Answer 2

Saphenous (femoral): medial malleolus and medial side of foot
Sural (sciatic): lateral malleolus and small portion of sole
Medial calcaneal (tibial): heel
Medial plantar (tibial): sole of foot; plantar surface of 3 ½ toes
Lateral plantar (tibial): lateral portion of sole; plantar surface of 1 ½ toes
Superficial fibular (fibular): dorsum of foot (except deep fibular area)
Deep fibular (fibular): dorsal surface between 1st & 2nd toes

Question 3

Describe the dermatomes of foot.

Answer 3

L4- big toe
L5- middle three toes and half of big
S1- pinky toe

Question 4

Describe the arteries of the foot.

Answer 4

Anterior Tibial Artery: through interosseous membrane; changes name at ankle (talus) to become dorsalis pedis a.

Dorsalis Pedis Artery: continuation of anterior tibial a.
Medial & lateral tarsal aa.
Dorsal (superficial) arch
Deep plantar branch (anastamose with plantar arch)
Dorsal metatarsal branches
Perforating branches (anastamose with plantar arch*)

Question 5

Describe the roots and origins of the following cutaneous nerves:
saphenous
sural
tibial
medial plantar
lateral plantar

Answer 5

Cutaneous Nerves:
Saphenous: from femoral (L3-4) covers medial edge of foot.
Sural: from tibial & common fibular (S1-2) covers lateral edge of foot.
Tibial: medial calcaneal branch of tibial (L4-5) covers the heel of the foot.
Medial Plantar: from tibial (L4-5) covers the medial sole including the first 3½ toes onto the dorsal surface; follows medial plantar a.
Lateral Plantar: from tibial (S1-2) covers the lateral sole and the last 1½ toes onto the dorsal surface; follows lateral plantar a.

Question 6

What is the plantar aponeurosis?

Answer 6

thickened deep fascia of the sole, extending from the calcaneal tuberosity to end in 5 slips over the heads of the metatarsals, and into the flexor tendon sheaths.

Question 7

What is the plantar reflex?

Answer 7

toes flex

Babinski sign: hallux extends & toes abduct

Question 8

Describe the dorsum of foot:
superficial fibular nerve
deep fibular nerve

Answer 8

superficial fibular nerve- cutaneous to most of dorsum of the foot except tips of toes

deep fibular nerve: 2 muscles (EHB, EDB) and sensory between 1st and 2nd toes

Question 9

Describe the plantar surface of the foot: Layer I

Answer 9

(AFA)
Abductor hallucis: medial plantar n; flex & abduct big toe
Flexor digitorum brevis: medial plantar n; middle phalanx of toes 2-5
Abductor digiti minimi: lateral plantar n; flex & abduct 5th toe

Question 10

Describe the plantar surface of the foot: Layer II

Answer 10

2M + 2T
Quadratus plantae: lateral plantar n.; inserts into lateral border of flexor digitorum longus tendons; assists in flexion of toes 2-5
Lumbricales: 1st lumbrical innervated by medial plantar n.; 2nd thru 4th innervated by lateral plantar n.; flex proximal and extend distal phalanges (similar to hand)

Tendon of flexor digitorum longus
Tendon of flexor hallucis longus

Question 11

Describe the plantar surface of the foot: Layer III

Answer 11

(FAF)
Flexor hallucis brevis: medial plantar n; 2 bellies; flexes metatarsophalangeal joint of 1st toe

Adductor hallucis: lateral plantar n; 2 heads (oblique & transverse); adducts 1st toe and helps maintain transverse arch

Flexor digiti minimi brevis: lateral plantar n; flexes metatarsophalangeal joint of 5th toe

Question 12

Describe the plantar surface of the foot: Layer IV

Answer 12

2M + 2T
Plantar interossei (PAD): lateral plantar n; adduct digits 3-5 toward midline (2nd toe)

Dorsal interossei (DABS): lateral plantar n; abduct digits 2-4 from midline (2nd toe)

Tendon of fibularis longus
Tendon of tibialis posterior

Question 13

Describe the posterior tibial artery.

Answer 13

Posterior Tibial Artery: divides beneath origin of adductor halluces m. into medial & lateral plantar arteries.

Question 14

Describe the medial plantar artery.

Answer 14

courses inferiorly to reach the medial border of the big toe.

Question 15

Describe the lateral plantar artery.

Answer 15

Lateral Plantar Artery: courses laterally distal to calcaneus to form Plantar (deep) Arch

Receives perforating branches from dorsalis pedis a.
Plantar metatarsal branches
Plantar digital branches
Terminal branch anastomoses with superficial arch between 1st & 2nd metatarsals*

Question 16

Describe the vessels and nerves of the plantar foot.
Tibial nerve
Medial plantar
Lateral plantar

Answer 16

Tibial Nerve also divides beneath the adductor hallucis m. into medial and lateral plantar nerves.

Medial plantar supplies AbH, FDB, FHB & 1st Lumbrical (LAFF), and continues as cutaneous branches to medial 3½ toes.

Lateral plantar supplies QP & AbDM, then divides into a superficial (FDMB, 4th Int) and a deep branch (AdH, 1st – 3rd Int), then continues as cutaneous branches.